House Democratic leaders still havenot been able to put together a majority among House energy conferees for the natural gas compromise, and in their search for votes are ready to jettison the crucial tax parts of President Carter's energy package.

House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) decided a year ago when Carter sent his massive energy bill to Congress that the only way to get the controversial tax and natural gas parts through the House was to package them with conservative assistance and other provisions. The House passed the program as one bill last year, but the Senate broke it into five bills.

Yesterday O'Neill signalled that he was ready to let approved parts of the bill pass separately. It was an effort both to satisfy election - time needs of members for an enacted energy bill and to pick up support for the recently negotiated compromise to remove federal price controls from newly discovered natural gas by 1985.

At the moment, O'Neill can count 11 of the 13 votes needed to win approval of the gas plan by the 25 House conferees. They have been meeting off and on with Senate conferees for more than six months, trying to settle differences between House and Senate versions of the energy package.

When O'Neill was asked at his daily press conference if he was ready to split the energy bill and let Congress take final action on parts that have been approved by House-Senate conferees, he had written answer prepared.

He said he hoped the conferees could agree on the natural gas pricing compromise in a week. Once that happens, he said he is "actively considering" letting House conferees attach their signatures to the four approved parts of the five-part package and let the Senate take them up for final approval. That could take some time if there is another filibuster against natural gas deregulation. The four parts would deal with gas, coal conversion, utility rate structures and a catchall conservation program.

Meanwhile, O'Neill said, the tax conferees could continue to try to reach agreement on a bill that includes the wellhead tax on domestic crude oil, which Carter calls the centerpiece of his conservation program. If a tax agreement has not been reached by the time the Senate votes on the first four parts of the bill, O'Neill is also "actively considering" having the House vote on them then and sending those parts to the president to be signed into law.

The two big-money and most controversial provisions in Carter's energy package are the proposals to raise the price of natural gas by deregulation, and oil by a tax to reduce use.

If O'Neill was right in his original analysis that the crude oil tax needed to ride piggyback on popular parts of the bill, cutting the tax parts adrift may further diminish chances of the crude oil tax. Even before yesterday's statement by O'Neill, the crude oil try was considered dead by many observers. The House approved it last year, but the Senate did not. Since then, an antitax climate has developed.

O'Neill said one reason for his readiness to cut loose the tax bill was hope that it would help pick up support for the gas bill. "If it doesn't, we have wasted a lot of time," he said.

O'Neill's problems among House conferees on natural gas have been mostly among liberals who oppose deregulation, which the Senate voted over the opposition of Carter and the House. Rep. Henry S. Reuss (D-Wis.), who had refused to vote for the gas compromise until assured the bill would not be held up to wait for the crude oil tax, which he opposes, indicated yesterday that O'Neill's statement had got him back in line.

But now the gas agreement is threatened with defections from producing-state members at the other end of he spectrum.

Reps. Charles Wilson (D-Tex.) and Joe D. Waggonner Jr. (D-La.) met with Carter yesterday and said they couldn't go along with the gas compromise as it stands. They oppose a provision that would end the right of producers to reopen contracts on gas consumed in the state where produced when another contract is signed to sell gas within the state at a higher price.

Negotiations are continuing with them on this issue. Waggonner said he believed agreement could be reached.

As things stand now, O'Neill needs both Wilson and Waggonner to ratify the gas compromise.

House conferees met yesterday afternoon to listen to an explanation by staffers of the gradual deregulation compromise. There were no votes, and the leadership apparently won't permit any until it is sure it has a majority or cannot ever get one. The House conferees will meet again this afternoon.

Meanwhile, the $13 billion Department of Energy authorization bill, which had been held hostage in an energy subcommittee as part of an effort to speed enactment on approved parts of the bill, was freed and sent to the full Commerce Committee for action.