President Carter finally got involved in the long-stalled natural gas pricing controversy yesterday, in an effort to save his energy bill from death by stalemate in a House-Senate conference.

As even the most optimistic congressional conferees began saying they had about given up hope of settling House-Senate differences on whether and how to remove price controls from newly discovered natural gas, Carter summoned 14 senior conferees to the White House. They met with him for an hour and with Energy Secretary James R. Schlesinger Jr. for another hour.

Schlesinger proposed compromise solutions which the conferees discussed with him and then took away for overnight study. They will meet again at the White House with Schlesinger at 7:30 a.m. today for 3 1/2 more hours of bargaining.

Henry M. Jackson (D-Wash.), chairman of the Senate conferees, said: "The president entered the talks at a momnt when the whole thing could have gone down the tube." He said he felt Carter's intervention had improved chances for a solution.

Thomas L. Ashley (D.Ohio), a senior House conferee, agreed that White House intervention had improved the outlook. "It's hard to walk out of the Oval office," he said, referring to threats that some of the conferees were about to walk out of conference meetings in the Capito.

Since discussions started last November, conferees have agreed tentatively to deregulate new gas by 1985. But they have bogged down on details involving huge sume of money, such as the definition of new gas that would qualify for the higher price, and incremental pricing, which would require big industrial users rather than home owners to bear the price increase up to a point.

A solution to the gas controversy has eluled Congress for 24 years, since the Supreme Court ruled that gas piped across state lines was subject to federal price control.

Last year the House approved Carter's plan to continue price controls, while the Senate voted with the gas industry to lift controls after two years.

Only one of the conferences since Christmas has been open to the public, but reportedly personal animosity as well as difficult policy issues have divided participants.

Sen. Jackson, one of the most optimistic about chances of reaching agreement, said yesterday before the White House meeting, "We are running out of time." He has fashioned a slender Senate majority behind a compromise, but it includes three Republicans who have served notice they will leave him if the issue is not settled by the end of this week.

Rep. Thomas L. Ashley (D-Ohio), a leading House conferee who has also been optimistic, about reaching agreement, said "the tenuous Senate majority will disappear if they perceive the House as insisting on issue after issue."

Carter says his energy bill is essential to reduce oil imports, now running at a rate of $45 billion a year.

Carter's main weapon to reduce consumption and imports is a stalled tax program headed by a tax on domestic crude oil. Congressional approval of that tax, which the House accepted but the Senate rejected, appears dim. But in any case consideration has been postponed by energy conferees until a resolution of gas pricing.

In his anti-inflation speech yesterday Carter said that if Congress does not act to reduce oil imports he will have to take administrative action. Most of his economic advisers have recommended that the president impose import fees on the foreign oil. This would have the effect of imcreasing the price of all oil in the United States after high-priced and low-priced oil are blended.