After a weeks-long impasse with Virginia Sen. Harry F. Byrd Jr. the Justice Department announced yesterday that President Carter will nominate two lawyers recommended by Byrd-appointed panels to fill U.S. judgeships in the state.

The action, which reaves two vacancies to be filled, is unlikely to still criticisms by Carter and Senate Judiciary Committee Chairman Edward M. Kennedy that the lists of 10 white men forwarded by Byrd should be expanded to include blacks and women.

A spokesman for Kennedy said confirmation hearings on the two nominees -- Richard L. Williams of Richmond and James P. Jones of Abingdon -- will be stalled until the names of the other two nominees are known. That adds further pressure on the White House to nominate a black or woman for at least one of the judgeships.

The president had threatened to leave the judgeships vacant if Byrd refused to expand the lists beyond the 10 recommendations for four judgeships, two each in eastern and western Virginia.

A spokesman for Attorney General Griffin Bell said yesterday, however, that the Justice Department was going ahead with two of the nominations because of the critical need to have additional judges attack the growing backlog of cases in the U.S. District Courts.

That argument apparently will not fly with Kennedy, who has adopted a policy of holding up hearings on any nominations until the names of all of the nominees within a state or judicial district have been sent to the committee.

Byrd interpreted yesterday's announcement, which he said he got in a telephone call from the attorney general, as an indication that the president will carry through on "a moral commitment" to select "the best qualified" nominees from among the recommendations of properly appointed judicial selection committees.

Rep. Herbert E. Harris II (D-Va.), another critic of the Byrd lists, saw Bell's statement as "a clear signal that Mr. Carter is in fact seriously searching for qualified women and minorities for the remaining two vacancies."

The White House said last night that because the president has not yet officially nominated Williams, a former state judge, and Jones, a Democratic party official, there could be no comment on the reasons behind his partial action.

A spokesman said the president "has not abandoned his commitment (to expanding the federal judiciary to include women and minorities) in any way."

One reason the president may have relented on his threat to hold back nominations is that Sen. Kennedy has made it clear he will not permit continuation of past practices of the Judiciary Committee that allowed a homestate senator to block all nominations not to his liking.

Kennedy has no intention of blocking the appointments of Williams and Jones, an aide said.

The aide said Kennedy hopes the nominations of a black and a woman for two of the four new judgeships in Massachusetts, on which hearings were conducted yesterday, will serve as an example to other state commissions.

Kennedy has indicated, the aide added, that any judicial selection commission that cannot find qualified blacks or women in its state "isn't worth its salt."

Rep. Harris and others have encouraged individuals and groups to send the names of potential judges directly to the Justice Department for consideration.

A spokesman at Justice said yesterday that more than a dozen black or female lawyers in Virginia have been recommended, although some of them are fairly recent law school graduates who lack the experience to qualify as candidates.

The spokesman said the attorney general discussed the nominations of Williams and Jones with the president and "we feel very comfortable with them."

The president will not make any formal announcement until the names of Williams and Jones have been scrutinized by the FBI and various bar associations.

Jones, 38, is the Democratic party chairman of the 9th Congressional District of Virginia. A graduate of Duke University and the University of Virginia Law School, he was a clerk to Chief Judge Clement F. Haynsworth Jr. of the Fourth U.S. Circuit Court of Appeals in Richmond before going into private practice in Abingdon and Bristol.

Williams, 55, was a judge of the state circuit court in Richmond from 1972 until 1976, when he resigned to return to private practice with the large and prestigious Richmond firm of McGuire, Woods and Battle.