After defeating a key amendment to give states the right to rescind their approval of the Equal Rights Amendment, the House yesterday voted 233 to 189 to extend for 39 months the time states have to ratify the measure.

While the vote was a significant victory for ERA supporters, the extension still faces a big hurdle in the Senate, where Sen. Orrin G. Hatch (R-Utah) has threatened a filibuster that would further tie up the backlogged chamber in the waning weeks of the session.

The key vote in the House yesterday came on an effort by Rep. Thomas F. Railsback (R-Ill.) to allow states that have ratified ERA to rescind that action.

House supporters of the ERA extension called Railsback's amendment "mischievous" and "destructive," and threatened to pull the bill off the floor if it passed.

Though the amendment was defeated 227 to 196, both sides had predicted a much closer outcome, and heavy lobbying continued until the last minute.

Women's groups, labor unions and the administration lobbied heavily against it. Nuns were sent to Catholic House members to insist that ERA was not tied to abortion. House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass) worked on several members to vote against recision.

Meanwhile, Phyllis Schlafly, head of STOP ERA, the key organization opposed to the extension, maintained a day-long vigil in a hall outside the chamber and worked with conservative groups, such as the American Conservative Union, for recision and against any extension.

The ERA has been ratified by 35 of the 38 states necessary to make it part of the Constitution. But in the past few years it has been bogged down in the remaining 15 states.

A seven-year deadline, set when the amendment passed Congress in 1972, expires next March 22. The extension would extend that limit until June 30, 1982.

March 22. The extension would extend that limit until June 30, 1982.

Railsback argued that, in fairness, the 35 states that have ratified ERA should be allowed to take back their votes. Four states - Nebraska, Idaho, Tennessee and Kentucky - have voted to rescind ratification. Railsback said his amendment would not sanction these actions, but would allow states to vote to rescind during the extended time period.

The courts have never ruled on whether such recisions are legal.

Rep. Don Edwards (D-Calif.), floor manager of the extension bill, said "the constitutionally established process in effect for 200 years would be sorely damaged" if recision were allowed. "The message would go out that Congress says ratification is conditional, that states would not have to take ratification seriously because they could rescind next year. It would make every state a battleground during every session . . . for every constitutional amendment in the future."

But Rep. Charles E. Wiggins (R-Calif.) argued, "What could be fairer than to give states the opportunity to vote either yes or no? Surely we're going to invite 15 states to vote aye. Let's not lock 35 states in artificially, which is what the opponents want to do."

Rep. Elizabeth Holtzman (D-N.Y.) said, "It is a two-way street. States can vote to ratify or not. But Railsback would make it a 100-way street," and invite chaos in the process.

Opponents of the extension also argued that since a constitutional amendment must pass the Congress by a two-thirds vote of each house, an extension also would require a two-thirds vote for passage.

But an attempt to offer a resolution to require a two-thirds vote was tabled 230 to 183.

Rep. Trent Lott (R-Miss.) said, "The seven-year extension was part of a total package passed by a two-thirds vote. Not to require a two-thirds vote on the extension flies in the fact of proper parliamentary procedure, not to mention the Constitution."

Lott said, "Why are we going through this agony and ecstasy, since the Senate will not act." He called it "an exercise in futility."

In one of the few emotional moments of the day-long debate, Rep. Barbara Jordan (D-Tex.) was applauded by spectators in the gallery when she replied, "Woman have been going through the agony and the ecstasy all their lives and we will continue to go through it until ERA is part of the Constitution."

On the Railsback amendment, Maryland Reps. Gladys Noon Spellman (D) and Newton Steers (R) voted no, as did Virginia Democrats Joseph L. Fisher and Herbert E. Harris.