The Senate Judiciary Committee plans to hold hearings next month on President Carter's controversial nominees for federal judgeships in Virginia, raising prospects of a possible showdown between the Carter administration and Sen. Harry F. Byrd Jr. (Ind.-Va.)

A key Judiciary Committee staff member said yesterday that the committee, headed by Sen. Edward M. Kennedy (D-Mass.), expects to schedule October hearings on nominees for all four newly established Virginia judgeships.

The controversy over the Virginia judgeships centers on Byrd's recommendation of 10 white male judicial candidates. Carter threatened in December to leave the Virginia judgeships vacant unless Byrd added blacks and women to his list.Byrd has refused, arguing that the candidates were selected by special citizens' advisory panels.

Despite his initial threat, Carter later nominated two of Byrd's candidates, Richard L. Williams and James P. Jones, for federal judgeships. The other two nominees are expected to be state Sen. J. Harry Michael Jr. (D-Charlottesville), a candidate backed by Byrd, and James E. Sheffield, a black Richmond judge who was not recommended by Byrd.

The Senate Judiciary Committee, which must confirm judicial appointments, has delayed action on the Virginia judgeships,saying it wanted to consider all four nominees at one time. It was unclear yesterday whether it would alter its plans for October hearings if Carter failed to submit the two remaining Virginia nominations by then.

A Byrd aide yesterday reiterated his previous warning of a possible "direct confrontation" between Byrd and Carter over the judgeships, but the aide did not flatly say that Byrd would oppose Sheffield's nomination.