Commonwealth Secretary General Shridath Ramphal urged today that the group create a peace-keeping force for Grenada to replace U.S. forces, which, he said, should be withdrawn from the island "very, very quickly."

Prime Minister Margaret Thatcher said in Parliament that she would "consider sympathetically" requests to join such a force.

The proposal that troops from some of the 48 countries in what was formerly the British Empire might be used to help Grenada through a transition period to elections is taken seriously here. The establishment of the unit would remove some of the sting of international criticism from the American-led invasion by taking it quickly out of the arena of superpower politics.

Grenada, which became independent of Britain in 1974, is a member of the Commonwealth, as are the Caribbean islands that joined the United States in this week's intervention. One possibility for creation of the peace-keeping unit is at a meeting of Commonwealth prime ministers in New Delhi early next month.

Ramphal has accused the United States of "blatant aggression" and said today, "I am looking for a withdrawal of the invading forces within a matter of days or weeks, not months." He said that the peace-keepers that were then sent in might be drawn from the greater Commonwealth or from other Caribbean countries, depending on the decision of the organization.

The Thatcher government's refusal to join the U.S.-led intervention has enabled it to preserve the image of neutrality that would minimize allegations that it is reviving a colonialist role by joining such a force. But Thatcher was careful today to hedge her positive response to the idea, as conditions on the island are still far from secure and no timetable for the U.S. withdrawal has been set.

Thatcher and a spokesman for Queen Elizabeth said today they were unaware that the governor general of Grenada, Sir Paul Scoon, had made a request for military intervention last week as was claimed yesterday by Eugenia Charles, prime minister of Dominica. "No request for intervention from the governor general was passed through British channels," Thatcher said.

A British diplomat who had a meeting with Scoon in Grenada over the weekend did not report any such request, sources said, nor was any relayed through the queen, her spokesman said.

Scoon, a Grenadan who worked for the Commonwealth Secretariat in London during the 1970s, was named governor general of Grenada in 1978. His appointment by the queen, who is Grenada's ceremonial head of state, is a remnant of the colonial period. He has no political connection with Britain whatsoever and receives no money or instructions from the queen, who scrupulously avoids any involvement in politics.

However, as a constitutional figure he would have the right to request outside intervention, according to British sources. The queen's spokesman said that Buckingham Palace had been in touch with Scoon as recently as last week, but not since the invasion began.

Scoon is expected to be a central figure in any provisional government established by the United States when order is restored in Grenada. He would preside over the island until elections can be organized.

In Paris today, Foreign Secretary Geoffrey Howe met privately with Secretary of State George P. Shultz to discuss Anglo-American differences over the Grenadan invasion, Washington Post correspondent Michael Dobbs reported. Shultz said later that, among other things, the possible role of Scoon was discussed.

Howe said that U.S. forces should "withdraw from Grenada as soon as possible so that action could be taken" on the island to bring about "democratic elections."