In June 1978, as in every year, O. D. Carpenter, head of the Atlanta division of Winn-Dixie Stores, the nation's fifth-largest grocery chain, called in his upper- and middle-level subordinates one-by-one to review their salaries.

Most got the happy news they expected: the Jacksonville, Fla., company was awarding each of them a bonus -- $2,000 or $2,500, in some cases -- and would build it into their base salaries.

Then, according to four of the men who agreed to talk to a reporter if their names were not used, Carpenter dropped the other shoe: he was solicitng contributions for the company's political committee (PAC). Some of what Winn-Dixie giveth, he was saying in a low-key way, its Sunbelt Good Government Committee would taketh away.

"You knew what the point was," one of the four men remarked, wryly.

"I gave in the interest of my career," another said frankly.

Winn-Dixie's Sunbelt PAC is one of the largest in the country. In the 1978 congressional campaigns, it ranked third on the corporate list in receipts and fourth in contributions.

Until 4 1/2 years ago, corporate PACs such as Sunbelt had a minor role in election financing, though business wealth, usually through personal contribution always had made itself felt.

In November 1975, however, the Federal Election Commission (FEC) issued an important decision legitimizing PACs. Since then they have proliferated into a major new force in U.S. politics. From 226 then, their numbers had risen to 784 by the end of 1978. In that year they took in $17.7 million.

That was still $2.1 million less than labor PACs, but the companies are plainly closing in on the unions. And these corporate-union figures understate the power shift, because they exclude rapidly growing industry and trade association PACs. Corporate PACs still have a lot of their growing to do, moreover, while labor PACs do not; almost all unions already have them.

The new corporate money-giving mechanisms are a major reason for a resurgence of business influence in state houses and on Capitol Hill.

Among other things in Congress last year, they helped defeat a "labor reform" bill that was a particular target of Winn-Dixie. Last year, over party-line Republican opposition, House Democrats approved restrictions on PAC giving. But the Senate -- again with the aid of business PACs -- has benched the bill.

The FEC ruling and then the 1976 election law amendment legitimized use of corporate funds to set up and operate PACs and to solicit employes. Perhaps ironically, this was a product of "reform" legislation, starting with a 1971 law and post-Watergate amendments, that organized labor had strived mightily to achieve.

The theory behind the ruling and the 1976 amendments was that employe contributions to corporate PACs would be voluntary, just as to union PACs. As Rep. Bill Frenzel (R-Minn.), a member of the House committee that writes election laws, has put it, "Every nickel that PACs contribute to candidates is voluntarily given by individuals."

But critics said it was only common sense to doubt that corporate career and professional employes -- persons unprotected by personal or union contracts, and dependent on their bosses' good will for promotions and raises -- give to PACs as the result of a free choice, rather than as the result of pressure or a desire to curry favor.

The testimony of the four Winn-Dixie employes, who will be called Brown, Jones, Adams and White, reinforces such doubts.

The four men, who put in a total of more than 70 years with Winn-Dixie, have left to go into businesses of their own or to take other jobs. By and large, they still speak warmly of the company. "I have a good career at Winn-Dixie," Jones said. None suggested that Carpenter, who declined to comment, had done anything but what he'd been told to do by the top brass, and none knew of any reprisals against anyone who refused to join Sunbelt.

Although Jones and Adams didn't join Sunbelt, White -- the foursome's executive -- and Brown did.

Did White's decision to contribute result from "free choice"? "No," he replied. The thought had crossed his mind, he said, that joining the PAC might win favor, while not joining might mean disfavor.

Brown, who "gave in the interests of my career," said he didn't feel at the time that refusing to join would be "necessarily a detriment" to his career. But, he said, "I had the feeling it would be a plus if I did."

Similar inner dialogues were recalled by the holdouts. Like the joiners, they said Carpenter, a Winn-Dixie vice president, used no heavy-handed tactics, but sent a clear message nonetheless.

"You knew what the hell the point was," Adams said. "He said he thought it was a good thing, and that it would help the individual [contributor] more than Winn-Dixie. Hell, you know better than that."

Despite a belief, shared by Jones and Brown, that his career depended totally on the good will of the company, Adams in the end didn't sign up, saying, "I didn't feel it would help me to contribute."

Also troubled by the solicitation was Jones, the other holdout. "It made you wonder if it would help your career if you gave," he said. "It made you wonder."

Like most corporate PACs, Winn-Dixie's gets most of its money from employes and stockholders. But Sunbelt is believed to be unusual in getting substantial sums from a group of stockholders who are executives of firms that do business with Winn-Dixie, selling them foods, supermarket equipment and other products and services.

Most of these executives said they believed in the political philosophy espoused by Winn-Dixie's top officers, trusted them to implement it and contributed to Sunbelt in response to pleas made to them as stockholders.

"They're conservative, we're conservative," said William W. Cook, whose Jacksonville advertising agency has more than $20 million in annual billings from Winn-Dixie. He and two other top executives of the agency, also stockholders in Winn-Dixie, gave $30,000 to Sunbelt in 1978 and 1979.

But another contribution was listed by Sunbelt from Val P. Thomas, who was not recorded as a Winn-Dixie stockholder and who is an account executive with an investment firm that does business with the PAC.

In the 15-month period that ended March 31, Sunbelt reported 8,889 in interest income from "Merrill Lynch Ready Assets Fund," and a contribution of $1,250 from Thomas, of the Jacksonville office of Merrill Lynch Piece Fenner & Smith. Under FEC rules, an outsider such as Thomas may contribute to a corporate PAC but may not be solicited.

Thomas said he gave to Sunbelt "imply because I believe in what they are doing." Was he solicited? Was there a connection between his contribution and the Sunbelt funds invested with Merrill Lynch? "I won't answer either question," Thomas told a reporter.

Another insight involved the widely held belief that most of all of Sunbelt's money for condidates goes to those who are opposed or unsupported by unions.

"They're antiunion, that's for sure," said Adams. Similarly, Dorothy Davis Smith of Kirkwood, Mo., a member of Winn-Dixie's founding family and owner of 33,800 shares of stock worth about $925,000, and she gives to Sunbelt because it is, "basically, antiunion."

The belief is understandable. Winn-Dixie, which operates nearly 1,200 stores throughout the Sunbelt and had 1979 sales of nearly $5 billion (and the industry's highest net profit margin) has defeated all union organizing efforts. It is a target of a continuing boycott by organized labor and its allies, and it is outspokenly antiunion.

Business PACs have "evened up the power between business and the labor movement," Winn-Dixie chairman James E. David said in January in a plea to stockholders to contribute 2 percent of their dividends to the PAC. "The loud cries of labor attest to this," he wrote. "As you know, from our letters last year, we were able to defeat the so-called 'labor reform' legislation."

But the former employes and several stockholders were astonished when the reporter told them the company's undoubted strong antiunion feelings leave few footprints on the reports filed by Sunbelt on the candidates who get its dollars.

Essentially, the reports show that Sunbelt, much like PACs sponsored by numerous corporations, unions and organizations of other kinds, contributes pragmatically, giving to candidates -- mainly entrenched incumbents -- who are or may become situated to help Winn-Dixie.

In the 39-month period that ended March 31, Sunbelt contributed to 123 House and Senate candidates, according to a Washington Post tabulation. They include 89 who got nearly $2 million for the 1978 primaries and election from assorted organized labor PACs, by the count of the AFL-CIO's Committee on Political Education (COPE).

For the same races, Sunbelt (or its predecessor, the Southeastern Good Government Committee) gave $152,191 to 87 House and Senate candidates. Of these, 44-52 percent -- had COPE endorsements.

Another indicator of Sunbelt's pragmatsm is its contributions to 18 of the 36 members of the Ways and Means Committee, the House tax-writing panel.

Among the 18: Chairman Al Ullman (D-Ore.), owner of 233 shares of Winn-Dixie stock worth about $6,400, and Rep. Charles B. Rangel (D-N.Y.), who represents Harlem. His district is hundred of miles north of the Mason-Dixon line and the nearest Winn-Dixie store. Ullman's district is thousands of miles away.

For the 1978 races, Sunbelt gave them $1,000 each, while union PACs gave $1,600 to Ullman and $12,000 to Rangel. An unsuccessful Senate candidate, Minnesota Democrat Wendell Anderson, got $2,000 from Sunbelt while getting 81 times as much -- $161,906 -- from union PACs.

Another aspect of the story is the secretive ways of Sunbelt and, for that matter, of numerous other PACs.

Sunbelt doesn't tell those who give it money who selects the candidates to get the money, doesn't tell them who those recipients are, and doesn't allow them to earmark their contributions for candidates of the donors' choice.

By contrast, many corporate PACs have what Bernadette Budde of the Business-Industry Political Action Committee (BIPAC) acclaims as "safeguards to voluntariness."

For example, the Corning Glass PAC sends out period newsletters telling its contributors who has received its funds and giving the receipients' backgrounds.

Going further, the Boeing Co. and Mead Corp. PACs accept contributions onlly if earmarked for particular candidates. PACs at other companies, including General Electric and General Motors, allow earmarking.

In addition, many corporate PACs insulate employes from some possible workplace pressures and assure confidentiality by ruling out solicitations by superiors and payroll deduction plans.

Sunbelt's secretiveness is a sore point with the four former employes.

Brown said he "just assumed" the candidate choices were made by the Davis brothers -- Chairman James, vice chairman A. Darius, vice chairman and senior vice president Tine W., and board member M. Austin. White "just assumed it was the executive committee" of the company.

Jones might have joined Sunbelt if it gave the names of the candidates it financed to the contributors. But, he said, "I didn't know the candidates they were backing, and I really resented it." His preference was to "give to people I believed in, but I want to make the judgment myself."

Brown, Jones and White are Democrats; Adams is an independent. None thought it mattered if Sunbelt money went to Republicans, reasoning that Sunbelt's purpose was to help Winn-Dixie without regard to party affiliations.

That reasoning is consistent with giving by traditionally Democratic members of the Davis family. In addition to bipartisan contributions to some of the same candidates favored by Sunbelt, four of them $4,000 to John B. Connally's campaign for the GOP presidential nomination -- and $2,000 to the Carter-Mondale Presidential Committee.

Coercion of contributions has been outlawed for almost 75 years. The Supreme Court and the federal government, in cases involving union members and federal employes, have warned that contributions must be "knowing free-choice donations," must not be solicited in "inherently coercive circumstances" and must not be made to "curry favor" with superiors.

The warning was taken into account by the FEC in its November 1975 ruling. The agency said it "recognizes . . . that there is in the best-intentioned plans a potential for coercion which is inherent in the employment relationship and which my be triggered by solicitations of employes by or on behalf of an employer."

To minimize "the appearance of perception of coercion," the FEC recommended a guideline to corporations: "no superior should solicit a subordinate."

The guideline was in the Senate version of the 1976 amendments, but was dropped in a House-Senate conference. The result was to allow solicitations by corporate officers of the subordinates.

In a pending court case, however, the International Association of Machinists contends that face-to-face solicitations of subordinates by superiors weren't what Congress had in mind.

Last year, the IAM complained to the FED that contributions by career and professional employes "reflect . . . the exigencies of the employment relationship" and consequently result in "forbidden indirect corporate political contributions . . . ." One of the union's cases in point: at Union Camp Corp., all payroll deductions to the company PAC were doubled at the same time, in July 1978.

The evidence in the IAM's complaint was drawn from reports filed with the FEC for the 1978 elections by the PACs of 11 companies: Amoco, sponsor of the largest corporate PAC at that time, Dart Industries, GE, GM, Grumman, International Paper, Union Camp, Union Oil, United Technologies and Winn-Dixie.

The complaint deduced from the evidence several reasons to suspect that "captive" career employes had contributed involuntarily. They joined the PACs in extraordinarily large proportions, the IAM pointed out. Their contributions were relatively large, and they delegated to the PACs the business of choosing candidates, a large share of whom were in distant states, the IAM said.