At the sumptuous Southampton Princess Hotel in Bermuda, three influential Maryland legislators spent several days this week in a setting of lush green golf courses, aquamarine waters and palm-studded sands -- their trip hosted and paid for by the Maryland Bankers Association.

At the same time, nearly 1,000 miles north in Annapolis, the banking bill one of them sponsored and another shepherded through an influential committee in the General Assembly, was signed into law by Gov. Harry Hughes.

The occasion for the outing, which ends today, was the bankers' association's annual convention. Last year the convention was held in Boca Raton, Fla. -- and all three legislators attended that, too.

Two of the legislators, Sen. Harry J. McGuirk, a prominent committee chairman from Baltimore, and Del. John R. Hargreaves, a Democrat from the Eastern Shore, said yesterday in telephone interviews that they saw no ethical problem with letting the bankers pick up their tab.

The third, Sen. Jerome F. Connell Sr., a Democrat from Anne Arundel County, could not be reached for comment.

"Nobody's going to buy me with a trip," McGuirk asserted.

He and Hargreaves said a day-and-a-half of the convention is crammed with technical work sessions, speeches and their own appearances on a panel.

The two legislators also performed a more unusual service for their banking hosts -- tending bar during the cocktail hour at what McGuirk called "the beautiful Eisenhower Suite" at the luxury hotel.

Rooms at the resort, a balconied, pink hotel perched atop a hill with a panoramic view of golf courses, beach and harbor, run upwards of $120 a night for a couple. Air fare from Baltimore, which also was picked up by the association for the legislators and their wives, would be $215 each, if they paid for it themselves.

Last year's free convention trip became a subject of controversy during the legislature's 1980 session when some legislators charged that it had helped smooth the way for a banking bill that raised interest rates on some loans by 50 percent.

The bill's sponsor, Connell, angrily responded that, "When I sponsor a piece of legislation, it's because I think it's good law, good for the banks and good for the consumers, or else I don't sponsor legislation.

"I could probably buy and sell you," he told a reporter at that time. "I have enough money to go where I want to go when I want to go. I don't need any bribes from anybody."

On Tuesday, shortly after the banking bill was signed into law in Annapolis, Connell, accompanied by the banking association's chief lobbyist, William K. Weaver, boarded a plane to Bermuda, according to Sen James C. Simpson, who also is attending the convention. Simpson, a bank director in Charles County, was there at his own expense and that of his bank.

The convention, attended by more than 750 bankers and their spouses, included a discussion of the importance of the association's political action committee that funnels campaign contributions to politicians, work sessions and the legislators' panel discussion entitled "Economic Development in the State of Maryland -- What It Means to the Banker."

Maryland House Speaker Benjamin L. Cardin said yesterday that such trips set up "two conflicting issues.

"It's extremely important for legislators to comingle with the business community . . . and the Maryland banking community is an extremely important group. There should be free mingling at meetings," he said. "I just wish they would have their meeting in Baltimore or at Hunt Valley (a suburb outside Baltimore) where you would have free access without raising in the public's mind this ethical problem."

Cardin noted that the trip in no way violates Maryland's ethics code, which requires only that legislators report the trip on statements filed with the ethics commission.

"But when you get to places so far away and so luxurious, it raises questions in the public mind," he added.

When the Boca Raton trip became controversial during the General Assembly, lobbyist Weaver said that the bankers' annual conference is an event "where senior banking officers . . . have a chance to get together with speakers who have a state and a national reputation" and is not considered a lobbying effort.

McGuirk Yesterday agreed, saying: "The only way to learn other people's business and your own business is to attend conventions . . . whether it's in Washington or Ocean City or Bermuda, the location's not important."