The Senate Foreign Relations Committee voted yesterday to lift a part of the U.S. trade embargo against Cuba and permit Havana to buy American medicines, agricultural supplies and foodstuffs.

In a separate action, the committee pulled the teeth from an amendment by Sen. Charles H. Percy (R-Ill.) aimed at dismantling the U.S. Information Agency and establishing an independent Voice of America.

The 10-to-7 Cuba vote came after two hours of debate on a proposal offered by Sen. George McGroven (D-S.D.) that originally would have permitted two-day trade in medical and agricultural supplies between the two countries.

Sen. Dick Stone (D-Fla.) called the proposal "a giveaway of many of our most valuable bargaining chips" in the talks with Havana launched by the Carter administration.

Stone, strongly opposed making any concessions to Cuba in the absence of reciprocal gestures by President Fidel Castro's government.

Again and again, Stone spoke of the 751 people with valid claims to U.S. citizenship who want to leave Cuba but stay because they cannot get permission for their family members to leave with them. "We seem to be getting a bit of light at the end of the tunnel," Stone said of the U.S.-Cuban negotiations that have already reached agreements on fishing zones and the size of fishing catches.

"This is the kind of thing that you negotiate, not the kind of thing you legislate," he said in asking the committee to reject McGroven's proposal.

Stone argued that U.S. sugar planters and citrus farmers would be seriously injured if Cuban produce were allowed into his date, Florida, and other areas. Florida is also the center of the Cuban exile community, which is overwhelmingly anti-Castro.

With a majority of the committee clearly opposed to his proposal, McGroven agreed to continue the ban on Cuban exports to the United States and permit only U.S. sales to Cuba.

Lifting the trade embargo one way might have little impact. Cuba would not have enough hard currency to make large purchases of U.S. goods if it could not sell its products to the United States government experts said.

Culver Gleysteen, a State Department Cuba expert and member of the U.S. team that is negotiating with Havana, told the committee he had instructions to say the administration neither supported nor opposed MCGroven's original proposal.

After the compromise was reached, Gleysteen made clear that the State Department had not favored lllowing Cuban sugar into the U.S. market at this time without receiving an equivalent concession from Cuba.

Percy's effort to order President Carter to reorganize the government's international information activities along the lines recommended by a report two years ago foundered for lack of votes.

Percy backed away and accepted a substitute that only requests the President to take into account the findings of all recent studies of the field, including the 1975 report, which was made by a private commission headed by former CBS chairman Frank Stanton.

After the committee meeting, Percy said he would continue to work to provide VOA a status in which it would be free from interference in its news operation by diplomats and bureacrats.

"We're nudging and nudging and moving closer and closer to getting a really credible Voice," he said.

Percy noted that there had been high-pressure lobbying against his proposal. "You're got to give the other side credit. They did a helluva job."

"I know where the opposition is coming from," he told the committee, referring to USIA. "It's a fiefdom. It a kingdom. They're all fighting to keep what they've got."

In other actions while considering the $1.6 billion foreign affairs authorization bill, the committee:

Voted unanimously to reverse a long-standing policy and grant U.S. visitor visas to members of foreign Commnist parties unless the Secretary of State certifies to Congress that an individual would be a threat to this country. At present, Communists are barred unless the Secretary of State grants a special waiver.

Often, McGroven said, such waivers are mistakenly seen as politically significant when they are given for personal or humanitarian reasons.

Approved 9 to 6 an amendment by Sen. Clifford P. Case (R-N.J.) cutting the U.S. contribution to the U.N. Educational, Scientific and Cultural Organization by about $9 million to demonstrate continuing U.S. unhappiness with the anti-Israeli and other political actions of UNESCO.

Approved an amendment giving the government stronger control over Radio Free Europe and Radio Liberty over the strenuous objections of Sen. Hubert H. Humphrey (D-Minn.). Further wrangles on the Senate floor and in the House are likely on the move by McGovern and Sen. Claiborne Pell (D-R.I.) to eliminate one of the two levels of management that run the stations.