Two top officials of Charter Co. made a half-dozen trips to the Bahamas to discuss business matters with fugitive financier Robert L. Vesco, the firm disclosed last night to the Senate special subcommittee investigation Billy Carter's dealings with Libya.

The disclosure was in a summary of these contacts prepared by Charter lawyers and read at a hearing by Lewis I. Nasife, president of Charter Crude Oil Co., a subsidiary. He testified that he had no personal knowledge of the contacts, which were made by others, and was not questioned.

The summary said the trips to Nassau, made during a six-month period ending in January 1979, had an ordinary commercial purpose: exploring the purchase of a Bahamian refinery designed for Libyan crude oil. "At no time was the name Billy Carter ever mentioned or discussed" in connection with this, the paper said, "Neither was intercession by Vesco with the Libyans, with whom he claimed to have influenced, and the Libyan government itself was not involved, the statement said.

The transaction involving the refinery -- the world's fifth largest -- is separate from the previously reported agreement by a Carter subsidiary to pay Billy Carter 5 cents to 55 cents for each barrel of crude he would get Libya to commit to the refinery. Nothing ever came of the arrangement, which has potential to yield Carter commissions as high as $55,000 a day.

The refinery matter is also separate from a purported conspiracy hatched from a purported conspiracy hatched by Vesco under which Libya would pay at least $15 million to influence peddlers to procure export Licenses for six military transport planes that Libya has paid for.

These issues and their possible interconnections and ramifications are being investigated by a federal grand jury in New York City and a Senate Judiciary subcommittee, as well as by the subcommittee looking into Billy Carter's connections with the Libyans.

The fights to Nassau were made by Raymond K. Mason, chairman and chief executive officer of the parent conglomerate, and J. Steven Wilson, who was senior vice president and chief financial officer. Wilson has left Charter, which is based in Jacksonville, Fla.

Mason first met Vesco in 1971, when Vesco headed a New Jersey company called International Controls. Not until three years later did Vesco become a fugitive to avoid standing trial on charges that he defrauded investors of millions of dollars.

According to the summary, Vesco phoned Mason in June 1978 about the posibility of Charter buying certain Texas and Canada real estate assets. this led to several meetings between Wilson and Vesco and, in September 1978, to a meeting of both Mason and Wilson with Vesco in Nassau. Charter decided not pursue the opportunity.

A reporter was told that Vesco and Mason had talks about possibly buying Paradise Island, a gambling resort in Nassau harbor owned by Resorts International, but the summary said nothing of this.

In the fall of 1978, according to the Charter document, the company decided to try to aquire Carey Energy Corp., including its holding company, Grand Bahama Petroleum Co. Ltd. The Carey enterprise owned 65 percent of the refinery, which had gone bankrupt because of inability to obtain the Libyan crude oil it was equipped ot process.

At Vesco's request, Mason and Wilson flew in late January 1979 to Nassau to discuss acquiring the refinery, but, the company said, the session produced no results because of efforts Charter had undertaken independent of Vesco.

In March 1979, when Charter acquired 20 percent of Carey Energy, the summary said, Vesco phoned Mason to claim a finer's fee of $5 million -- $1 million more than Charter paid for the facility itself.

Mason, telling Vesco he hadn't earned a finder's fee, refused to pay it. Talks ceased until July 1979 when, after several phone calls, Vesco reduced his demand from $5 million to $250,000. He got nothing and eventually stopped phoning, the summary said.

A finder's fee was paid, however, to Robert R. McGrath, who, like Vesco, is a resident of Nassau and whose company, Oil Agents Inc., is incorporated in Panama. The size of the fee was not disclosed in the summary but was believed to be large. Charter officials refused to say what it was. McGrath could not be reached.

Attached to the summary was a letter to Peter Evans of Cooper & Lybrand, the accounting firm that was the bankrupt, in which McGrath said he had "absolutely no connection of any nature with the infamous Robert Vesco."