As the 1986 session of the Maryland legislature drew to a close last month, Montgomery County businessman James S. Culp took state Sen. Howard A. Denis out to lunch in Annapolis and handed him a check for $1,000. It was the largest single campaign contribution that Denis, a Bethesda Republican, had received in his 10 years in local politics.

"I was stunned," Denis recalled last week.

Just as startling to Denis was the source of the legal contribution. The check was signed by Robert O.C. Worcester, executive director of Maryland Business for Responsive Government. Denis knew nothing about the organization.

Today, Denis and most of the other 187 members of the Maryland General Assembly know all about MBRG. And well they might, for the well-financed coalition of 18 of the state's largest corporations has launched a campaign to convert the state Senate and House of Delegates into allies of big business.

The coalition's strategy for the fall elections is simple: Bestow money, endorsements and campaign support services such as telephone banks and volunteers on candidates it believes will work for a more hospitable economic climate in the state. One tool it used for the first time this year is a "report card," which it compiled at the end of the General Assembly session, listing how lawmakers voted on business issues.

Yesterday, statewide groups representing teachers, senior citizens and environmentalists joined with several black lawmakers to criticize the coalition's activities. The group also was denounced last week by the Maryland branch of the AFL-CIO.

Several of the groups objected to the report card, which some characterized as a "hit list."

Worcester disputes the phrase. "The term lacks dignity," he said. Still, he did acknowledge in a recent interview that one of the coalition's major aims is to see certain candidates defeated at the polls.

"The corporations that fund me want results, and I'm not going to lull myself into saying 'tomorrow,' " Worcester said. "We're going to direct support to the opportunity races."

In an era when special interest groups across the United States are playing an increasingly important role in local and state elections, the prospect of a political coalition with resources like those of MBRG has daunted more than a few Maryland politicians and their allies.

Modeled after similar, successful efforts in several Sun Belt states, MBRG and its political arm, Maryland PAC, already are bringing impressive resources to bear on a number of races around the state. MBRG is funded by $10,000 annual membership fees paid by each of its 18 members; Maryland PAC, which raised $86,000 last fall, has made $1,000 contributions to 20 candidates statewide and now has a cash reserve of $48,000.

Democrats and Republicans alike are predicting that those resources will have a profound effect on the business of getting elected to office in Maryland.

"Their issues are Neanderthal, but sure, they're going to have an impact," said Del. Michael R. Gordon, a Democrat from Rockville.

Gordon was one of 12 legislators who received a zero percentage rating on the report card, which looked at such issues as workers' compensation, unemployment insurance and subminimum wages for unemployed teen-agers. Legislators who voted for all of the key probusiness bills received a score of 100 while those who voted against all of them scored zero.

Worcester, a 42-year-old former college executive, says the MBRG's opportunities are nowhere greater than in Montgomery County, a vote-rich enclave whose constituents, he contends, are more business-oriented than its elected representatives. The county's 21-member state House delegation includes 15 men and women who received scores of 30 or lower in the coalition's rating.

Worcester's efforts in Montgomery began last summer, when heurged several private lobbyists, including those for the local Board of Realtors and the Bethesda-Chevy Chase Chamber of Commerce, to recruit a candidate to run against Dels. Idamae Garrott and Lucille Maurer. The two liberal Democrats from Silver Spring are competing for a seat in the state Senate.

"What I heard was, ' Maurer doesn't listen real, real good, but she listens better than Idamae,' " Worcester recalled. In the end, Worcester backed off his request for an alternate candidate.

In addition to the $1,000 contribution to Denis, who is in a tight Senate race with Del. Marilyn Goldwater (15 on the coalition's scale, compared with Denis's 60), the business group bestowed a $1,000 contribution on one other Montgomery politician, conservative Democrat Joseph E. Owens. The House Judiciary Committee chairman earned a 100 percent rating even though he missed six of 14 key business votes.

That the coalition was finally being heard was evident in late April, when state Sen. Laurence Levitan (D-Montgomery) boasted to an audience of Potomac Chamber of Commerce members that he had received the best business rating of the county's seven-member Senate delegation. MBRG had given Levitan a 90.

Also late last month, James A. Klein, a political newcomer and Democrat who wants to run for the House of Delegates in Gordon's Rockville district, called Worcester to inquire about MBRG endorsing his first bid for elective office.

What galls Worcester about the performance of most Montgomery legislators is data an MBRG consultant compiled about the county last year that he says show widespread support for business among residents of all of its seven legislative districts. Vern Kennedy, a conservative, Louisiana-based pollster, surveyed 1,200 Maryland residents and found broad sympathy for MBRG's goals, according to Worcester.

The survey found, for example, that the district around Rockville had a 58 percent probability of supporting a probusiness candidate. Yet, according to MBRG's report card, the three delegates in the district rated a total of only 21 percent.

Similarly, Levitan's nearby district, which showed 78 percent support for probusiness candidates, is also the base of Democratic Del. Gene W. Counihan, who rated a paltry 7 percent in the MBRG report card.

Counihan contends that the coalition's rating was deceptive because it ignored his sponsorship of legislation this year to establish small-business advice centers around the state and to help merchants collect on customers' bad checks. The General Assembly enacted both measures.

"Big business in Maryland does not have the same issues as local business," Counihan said. "The local business community regards me as a friend."

Indeed, the Bethesda-Chevy Chase Chamber of Commerce, which represents 700 merchants, gave Counihan a 58 percent rating for votes he cast in the same period covered by the MBRG report card.

"Individual types of businesses have their own agenda," said Jim Goeden, the chamber's veteran lobbyist. "These ratings are not perfect, but they are a useful tool."

Robert Zinsmeister, the director of governmental affairs for the Prince George's County Chamber of Commerce, said the MBRG has done little field work there because the Kennedy survey found the county to be generally less responsive to business concerns.

The Maryland coalition, founded in 1983 by eight large Baltimore companies, was modeled after similar groups in the Sun Belt that sought to improve the generally receptive business climate in that region. One of them, United for Arizona, was founded in that state in 1978 as a nonprofit corporation to provide advice to about 70 business-related political action committees.

Today, there are 150 such PACs in Arizona, said Margaret Walker, the group's director.

In Louisiana, business groups armed with Kennedy survey data won passage of that state's right-to-work law in the mid-1970s; in Mississippi, business groups helped probusiness candidates win seats in the state legislature three years ago, Worcester said.

Worcester, who has traveled to Arizona and Mississippi to see the business groups firsthand, and other MBRG leaders doubt that all of the other groups' strategies can be applied in Maryland, where the only certain thing about the legislature is its unpredictability on business issues.

"We have to work through the standard political process of Maryland," said coalition leader James Culp. "We're not headhunters, and we're not trying to make a power play. Our legislators have to stand on their voting records."

MBRG members are Baltimore Gas & Electric Co., C&P Telephone Co. of Maryland, Crown Central Petroleum Corp., Equitable Bancorporation, First Maryland Bancorp, Maryland National Corp., McCormick & Co., Mercantile Safe-Deposit and Trust Co., Monumental Corp., Noxell Corp., Perdue Farms Inc., PHH Group Inc., Potomac Electric Power Co., Preston Trucking Co. Inc., Sovran Bank Maryland, Tate Industries, Union Trust Bancorp and USF&G Insurance.