A senior Soviet military official was quoted today as having indicated that the Soviet Union is now prepared to consider a proposal to limit nuclear missiles in Europe that both Washington and Moscow rejected last year.

Marshal Sergei Akhromeev, the first deputy chief of the Soviet general staff, was quoted by Rep. Thomas J. Downey (D-N.Y.) as saying that the plan informally worked out by the U.S. and Soviet negotiators in Geneva was "not formally proposed" and that the U.S. negotiator, Paul H. Nitze, was "chastised by the Reagan administration" for it.

"But if such proposal is offered again, it would be negotiated," Downey quoted the marshal as saying.

The plan developed by Nitze and his Soviet counterpart, Yuli Kvitsinsky, reportedly would have reduced the Soviet SS20 rockets aimed at Western Europe from about 240 to 75, to be matched by deployment of an equal number of U.S. cruise missiles--but no Pershing II ballistic missiles--in Western Europe.

The discussion of the Nitze-Kvitsinsky formula and Akhromeev's remarks appeared to presage a possible shift in Moscow's position. So far, the Russians have refused to engage in such debates and Moscow's political and propaganda drive has been aimed at preventing the installation of any of the 108 Pershing II and 464 cruise missiles in five West European countries. The deployment is scheduled to begin in December.

The debate on arms control was one of four areas of discussion this week between Soviet officials and 19 visiting members of Congress led by Rep. Thomas S. Foley (D-Wash.), the majority whip. The current visit is the first by such a congressional team to Moscow since 1979.

Another visitor here this week, West German Chancellor Helmut Kohl, hintedyesterday that he had heard some "new" ideas from Soviet President Yuri Andropov on how to break the deadlock in the Geneva talks on missiles in Europe.

In a press conference tonight, Downey also touched on the parallel Geneva talks on strategic nuclear missiles, saying that Akhromeev had expressed interest in a proposal under which the United States would put off testing of the MX missile for one year in exchange for a ban on testing of the Soviets' new 10-warhead SS24 ballistic missile.

"I have no authority to make such a proposal nor do you," Downey quoted the marshal as saying. "But it is a serious proposal, which would be given serious consideration."

Downey said Akhromeev did not express the usual Soviet surprise at the mention of the Nitze-Kvitsinsky "walk in the woods" framework, so called because it was worked out during a walk in the woodlands near the site of the Geneva talks.

"He was well aware of the substance of the proposal and at one point corrected me" on a detail, Downey added.

While not disputing the accuracy of Downey's remarks, Rep. Dick Cheney (R-Wyo.) said he came away "with a slightly different impression." Cheney said Akhromeev's response should be taken in the context of belligerent remarks made by top Soviet leaders in recent days and their apparently unyielding position in Geneva.

If Moscow intended to signal a change in its position, Cheney said, "It should do so at Geneva." Moreover, he added, Akhromeev "did not comment on the merits" of the Nitze-Kvitsinsky concept.

Downey and Rep. Norman Dicks (D-Wash.) said that Akhromeev "responded in great detail" to questions on the balance of forces in Europe. They quoted the marshal as saying that "the fundamental thing is the British and French missiles" rather than the number of aircraft on both sides. "We can agree on this matter," he said, referring to aircraft.

Speaking about Moscow's view of the reduction of its medium-range missile force, Akhromeev was quoted as saying, "We will draw a line in the Urals and not deploy west of that line."

Another senior Soviet official, speaking privately about the Nitze-Kvitsinsky formula, was quoted by Downey as saying that he had reservations about the proposed 75 launchers on both sides.

"The numbers would have to be discussed," the official was quoted as saying. "If we could place them east of the Urals instead of destroying them, that would be easier for us."

Reports of the Nitze-Kvitsinsky plan last winter, however, suggested that it would have barred transfer of SS20s to Asia by linking the 75-missile limit in Europe to a freeze on SS20s east of the Urals, then estimated at 90. In February President Reagan, spelling out four "sound principles" for any European missile agreement, ruled out acceptance of Moscow's shifting of SS20s from Europe to Asia.

At tonight's news conference, delegation leader Foley said the purpose of the congressional trip was to help "create atmosphere that can lead to an improvement of relations" between the two countries, which have deteriorated sharply since Moscow sent its troops into Afghanistan in December 1979.

Both Soviets and Americans described the talks here as "tough and direct." Rep. Timothy Wirth (D-Colo.), who visited Moscow with a congressional delegation in 1979, said he was struck by how "dramatically" relations had worsened.

Rep. Henry Waxman (D-Calif.), who headed a panel on human rights issues, said members of the delegation had raised such concerns as restrictions on Jewish emigration and the problem of family reunifications. He said the Soviets had rejected the expressions of concern on these matters as an "interference" in their internal affairs.