A Libyan foreign agent yesterday said two top officials of the Carter-Mondale Presidential Committee knew he had been appointed to head a special campaign committee charged with winning Arab-American votes.

On Wednesday, campaign committee chairman Robert Strauss, one of the two, said the campaign had no such committee, that any contact with the agent, Washington lawyer Richard O. Shadyac, was completely "unauthorized" and that he had never heard of Shadyac.

Shadyac, who receives $4,000 a month from the Libyan government, said White House assistant for ethnic affairs Steven Aiello asked him to fill the post and told him that both Strauss and Carter-Mondale campaign manager Tim Kraft had cleared the appointment.

Shadyac said he has had several meetings in the last two months to discuss the committee's composition and duties with Aiello, two other White House aides and campaign ethnic affairs coordinator Franklin Lopez. Similar meetings with Kraft that had been scheduled for June 10 and July 25 were canceled, Shadyac said.

"I never sought this job in any way, shape or form," he said. "I can't believe they're denying it." Shadyac said he had been reluctant to take the position because of other commitments but that he decided to take it after Aiello assured him that "the matter had been cleared by Strauss and Kraft."

Attempts to reach Aiello for comment yesterday failed.

A Carter-Mondale campaign committee spokesman denied that either Strauss or Kraft had authorized Shadyac's appointment or the creation of an Arab-American group. "If [Aiello] offered any role in the Carter-Mondale presidential committee to this gentleman, it was without authorization," the spokesman said.

Kraft has "heard of Shadyac," the spokesman added, but only as "a possible fund-raiser." Meetings with him "to discuss fund-raising may have been proposed but never took place," the spokesman said.

In a letter sent to Shadyac Thursday, Strauss apologized for the "unfortunate confusion" that has Shadyac convinced he is head of an Arab-American campaign committee.

The campaign plans no such ethnic committees, wrote Strauss. "Apparently, one or more of our people, well-motivated but without any authorization whatsoever to do so, had led you and others to believe something to the contrary."

The dispute about Shadyac's role in the Carter campaign follows controversy about Libyan dealings with Billy Carter, the president's brother.

Ties between Libyan foreign agents and the U.S. government are controversial because Libya is avowedly anti-Israel and has helped fund, arm and shelter international terrorists. Shadyac, who chairs the Libyan-funded Arab American Dialogue Committee, reports to the same Libyan government official named by Billy Carter as his contact in papers he filed Monday registering himself as a Libyan agent.

Accounts of Shadyac's heading a special campaign committee have even reportedly divided the U.S. Arab community. Rather than an Arab-American committee, Lebanese here have urged the creation of a Lebanese-American committee, Carter-Mondale ethnic coordinator Lopez said earlier this week.

In addition, Jewish groups have criticized remarks Shadyac made about Israel's political influence. According to Shadyac, Aiello said that "considerable pressure had been exerted to terminate the comittee and to terminate the chairman of the committee."

Shadyac was interviewed by telephone yesterday from Germany, where he was stopping en route back to the United States from a trip to Libya.