Millionaire insurance man Harry W. Rodgers III today gave his own businessman's side of the issue being argued in the political corruption trial in which he, Gov. Marvin Mandel and four other men are defendants.

Rodgers, the third defendant to testify, admitted on the witness stand that he once asked the governor if he'd like to come to" the Tidewater Insaurance Co., run by Rodgers and two codefendants, once he was out of office.

Rodgers also supported previous testimony by Mandel and codefendant W. Dale Hess about an Eastern Shore Development scheme and the purchase of the Marlboro Race Track in prince George's County. Unlike the two who testified before him, Rodgers emphasized the business rather than the political aspects of the transactions.

The $350,000 Ray's Point farm venture on the Eastern Shore - one of the major transactions that the prosecution alleges were bribes - was. in Rodgers' words, an example of the "50 to 100 transactions I've been in where the most I ever put up was maybe $500."

Among the things that the federal indictment charges is that Rodgers, his brother William A. Rodgers Hess Irvin Kovens and Ernest N. Cory Jr. gave $350,000 worth of favors to Mandel in return for the governor's promotion of racing legislation.

The legislation was under consideration during the 1972 General Assembly session when Mandel's codefendants were secret owners of the Marlboro Race Track. The legislature's vote to override a Mandel veto, allegedly with Mandel's blessing, led to windfall profits for the track and another bill, promoted by Mandel but defeated, would have added further profits.

After that session Mandel and Rodgers, with their wives, took a vacation at a Boca Teeca. Fla. resort along with other godefendants as guests of Kovens.

"Mr. and Mrs. Mandel were not getting along too well," Rodgers said. "Irv Kovens thought . . . it might be a good thing to patch it up."

However, "it didn't work out too good." Rodgers explained, adding an entirely new aspect to the trip which is one of the prosecution's examples of the benefits alledgly given Mandel.

Since the defense began its case, the 1973 separation and 1974 divorce of Mandel from his first wife Barabar has grown in significance as an element in the last major issue to be argued - the motivation of the defendants.

Hess, who completed his testimony this morning, said that a $140,000 partnership agreement he made with Mandel in 1972 was a generous open-ended arrangement in part to heop the governor through his "personal and fiancial difficulties" with his former wife.

Assistant U.S. Attorney Ronald S. Liebman completed his cross-examination by attacking Hess's assertion that he deliberately warned friends not to tell Mandel that he and the other codefendants were the Marlboro owners. The prosectution contends that Mandel did know and that he promoted the legislation in return for benefits.

"You never told Newton Brewer (the state racing commissioner), not to tell Mandel," Liebman reminded Hess, and then listed off bankers, race track figures, attorneys and others associated with the governor whom Hess had not talked to.

"There was no need to becuse you had already told the governor, isn't that so?" Liebman asked, Hess firmly denied that, supporting Mandel's testimony that his friends hadn't told him until 1975, three years after the important legislative action.

Several character witness testfied to Hess's honesty and then the executive secretary of the state racing commission was called to the stand by Thomas C. Green, attorney for Harry Rodgers.

James A. Callahan testified that letters sent to the commission in 1972 concealing the true owners of the Marlboro Race Track conformed with "the practice and procedures" of the commission at that time.

Callahan also said it would have been "relevant" for the commission to know the names of the true owners, an opinion not shared by Carle A. Jackson another member of the commission who testified earlier on behalf of the prosecution.

Rodgers did not complete his testimony about Marlboro before the court adjourned today but he did testify about the business ethics of giving Mandel a 10 per cent share in the $350,000 Ray's Point Eastern Shore venture without requiring the governor to put up more than $150.

"If we hadn't give him (Mandel) an opportunity to come in. I think if would have been unethical," Rodgers said.

Mandel was included in the venture as a "finer" along with former Speaker of the Maryland House of Delegates Thomas Hunter Lowe, Lowe actually found the property but Mandel, Rodgers said, alerted him and Hess of the promising piece of property and therefore deserved a finder's status.

Mandel's name was not put on the any stock certificates and his name was erased from minutes of the corporation set up to purchase the property.

Once news of the venture became public and was published in newspapers eight months later, Mandel and Lowe bowed out of the deal. Mandel lost his $150 contribution. Rodgers said, but Lowe received a commision of about $15,000.

Rodgers who was one of Mandel's major fund-raiser in both gubernatorial elections, also supports Hess's stroy of a diamond bracelet gift for Mandel's former wife.

He said he agreed with Hess to pay half of the $4,500 cost of the gift, but denied that he did so to influence the governor's official actions.

"I'm not sure the governor knew," Rodgers insisted. "I'm not sure Mrs. Mandel knew either, because she never thanked me."

Of the Marlboro race track purchase Rodgers said it was a sound business deal, especially good since "the real estate alone was worth $1.5 million." It was the first mention of the value of the property itself as opposed to the value of the track in tthe racing industry.