An extension of time for ratification of the Equal Rights Amendment yesterday cleared another hurdle in the House as the Rules Committee voted to bring the measure to the floor.

The extension is expected to come to the floor before the Aug. 19 recess. It is given a good chance to pass the House, but its fate is uncertain in the Senate, where at least one senator has threatened to filibuster against it.

The Rules Committee rejected by an 8 to 8 vote a move by Rep. Trent Lott (R-Miss.) to have the House vote on the question of whether at two-thirds vote for passage is needed for the extension.

A two-thirds vote is needed to adopt a constitutional amendment, but supporters of the extension argue that two-third would not be needed, since it is not a part of the amendment but simply a procedural question.

Opponents of the extension have argued that any change in the amendment would require a two-thirds vote.

Though the two-thirds vote question is likely to come up again when the extension comes up on the House floor, it could be ruled out of order on the grounds that it is in fact only a procedural point, not requiring two-thirds.

The extension adopted by the House Judiciary Committee would extend the March 22, 1979, deadline for states to ratiefy the ERA until June 30, 1982, a period of little over 3 1/4 years.

As of now, the ERA is three states short of the 38 states necessary to ratify a constitutional amendment, and its supporters feel they will not get the necessary approvals by next year.

Opponents of the extension argue that it is unfair to give ERA the extra time. Rep. James H. Quillen (R-Tenn.) said it was "like giving Pete Rose another strike" so that he would not break his hitting streak.

"This is not a baseball game. This is a matter of human rights", Judiciary subcommittee Chairman Don Edwards (D-Calif.) said. He said the issue was still vital and alive and should not be arbitrarily cut off.

But Rep. Charles E. Wiggins (R-Calif.) said, "The process of amending the Constitution is also not a game, and we should not be party to a maniplusative process."

One issue that will come up on the floor is whether states which have already ratified the amendment will be allowed to rescind that ratification.

Rep. Thomas F. Railsback (R-Ill.) said he will offer an amendment allowing states to rescind, the legality of which has never been decided by the courts. Idaho, Tennesse, Nebraska and Kentucky have voted to rescind ratification of the amendment.