The United Mine Workers and a leading independent coal company reached a tentative contract settlement last night as the Carter administration's proposals for a governmental solution to the 77-day coal strike ran into trouble on Capitol Hill.

Administration and union officials expressed hope that the proposed Pittsburg and Midway Coal Mining Co. settlement would set a pattern for an agreement to end the record-long nationwide coal walkout.

There were also reports that Labor Secretary Ray Marshall would use the P&M settlement as a basis, although not neccessarily an exact formula, for a government-drafted contract offer to be submitted to the union and the coal industry on Wednesday.

This was a new departure from the options for "definitive" governmental action to end the strike that were outlined earlier by the White House: a back-to-work injunction under the Taft-Hartley Act, temporary government seizure of the struck mines or binding arbitration of the contract dispute.

Taft-Hartley, under which the president could ask the federal courts to order the 160,000 strikers back to work for an 80-day cooling-off period, has been given low priority by the administration because miners have defied injunctions in the past and would be expected to do so again.

The other two options, seizure or arbitration, would require congressional approval. In meetings yesterday between Marshall and congressional committee leaders who would handle any emergency coal legislation, senators urged continued efforts to reach a negotiated settlement, warning that any strike legislation could interfere with Senate debate on the Panamal Canal treaties and harm chances of the administration's labor law overhaul package.

Taft-Hartley was last used by President Nixon in 1970 in a West Coast dock strike. The coal mines were last seized in 1946 by President Truman, who also used a threat of seizure in 1950 to force a negotiated settlement in another coal dispute. In 1952 Truman tried to seize the steel industry but was rebuffed by the Supreme Court which held that presidents had to get congressional approval before taking over strike-bound industries.

The P&M settlement was negotiated over the weekend, apparently with White House encouragement, and approved 26 to 13 last night by the UMW's once rebellious bargaining council.

It was the 39-member council of top national and regional UMW leaders that triggered the current national contract stalement - and reluctant administration involvement in the dispute - by rejecting a proposed nationwide contract eight days ago.

P&M is a Denver-based Gulf Oil Co. subsidiary with 700 miners at six mines in western Kentucky and along the Kansas-Missouri border. It is one of the largest of the independent companies together employing a total of about 8,000 miners, that do not belong to the Bituminous Coal Operators Association but normally go along with the 130-member industry bargaining group's settlements.

The proposed P&M contract conceded more to the union than the BCOA di in its "final" settlement proposal last weekend. It would limit wildcat-strike disciplinary procedures to strike instigators and pickets, and restore cost-of-living increases as well as company-paid royalities to the UMW for processing nonunion coal through UMW-organized mines. It also excludes BCOA-proposed production incentives and 30-day probationary periods for new miners, sources said.

The economic package was basically the same: hourly wage increases of up to $2.40 over three years. Wages now average $7.80 an hour. The BCOA had offered $2.35.

Still at issue is the key question of benefits, including guarantee of medical and pension payments and BCOA-proposed deductible of up to $700 a year for health care. P&M reportedly agreed to go along with BCOA on these matters, which have been major sticking points in the past.

There was no immediate response from the BCOA, whose agreements with the UMW cover roughly half the coal produced in the country. The association had made what was described as its "final" offer during pre-dawn negotiations at the Labor Department last Saturday, which were broken off when the union's bargaining council unanimously rejected the industry proposal.

Presidential press secretary Jody Powell described the P&M tentative pact as "an interesting development that all parties ought to seriously assess."

The agreement is tentative because the 700 P&M miners must still ratify the agreement, a process that is expected to take about a week. Any national contract also would have to be ratified by rank-and-file miners under a 10-day time schedule.

Although a P&M settlement could start coal moving shortly to coal-starved Midwestern and Mid-Atlantic regions, where power cutbacks and job layoffs are threatened, its immediate significance lies in the effect it may have on UMN-BCOA negotiations, officials said.

Merlin Breaux, a Gulf Oil vice president who led the P&M negotiations, said it represented a compromise and left other coal companies with the alternatives of accepting the P&M pattern, continuing negotiations or letting the administration act.

It was clearly the first alternative that congressional leaders were looking to as Marshll shuttled from office to office on Capitol Hill, seeking guidance and trying to escalate pressure for an under-the-gun negotiation settlement.

He got lots of sympathy but not much encouragement for a congressional solution. Senate Majority Leader Robert C. Byrd, who also represents West Virginia, a major coal-producing state, said he favored continued negotiations over either congressional action or Tart-Hartley, which he said he would favor only as "matter of last resort."

Meanwhile, AFL-CIO President George Meany told reporters that, if he were president, "I'd seize the mines and lay down conditions the miners could accept."

But Meany said he wouldn't criticise Carter if he invoked Taft-Hartley, despite organized labor's general hostility to use of injunctions to end strikes. "It's up to him, I wouldn't criticize him," Meany said as the AFL-CIO Executive Council convened for its mid-winter meeting in Florida.

Meany said he talked by telephone yesterday morning with Marshall and concluded that the President was leaning toward seizure.

The UMW left the AFL-CIO years ago, but the labor federation endorsed the mine workers' strike last December.