The long night of negotiating was over, but approval of a new soft-coal contract by 160,000 United Mine Workers and a quick end to their 82-day-old strike appeared in deep jeopardy yesterday.

Neither industry nor union officials would predict certain approval of the agreement and ratification -- a process that will take up to 10 days --seemed an iffy proposition.

The first dark sign came from Kansas, where by a vote of 85 to 70, UMW members rejected a separate contract with the Pittsburg & Midway Coal Mining Co. Although negotiated separately, it is quite similar to the national agreement announced Friday night.

The UMW's tentative accord with P&M, a major independent operator with six mines in Kansas and Kentucky, provided the pattern for the proposed contract that UMW members will vote on elsewhere.

A UMW local official at Pleasanton, in eastern Kansas, said he believed miners rejected the P&M proposal because the national agreement was more favorable. The separate agreement was scheduled to be voted on by 570 P&M employes at UMW locals in Western Kentucky late yesterday and Monday.

Meanwhile, despite an implied threat of federal seizure of the mines and President Carter's appeal to miners' partriotism, rank-and-file UMW members in one coal community after another openly expressed disdain yesterday for the national contract.

The agreement, announced unexpectedly Friday evening by Carter on national television, temporarily eased jitters over severe electricity cutbacks and massive industrial layoffs that loom in the Midwest and South.

But the upper hand for now moved clearly to the miners, who, by their ratification vote, will determine whether to end what has become a full-scale national drama, freighted with presidential prestige and the prospect of large-scale bardship from energy shortages.

The agreement reached Friday, just hours before Carter had planned to address the nation and announce "drastic" actions, was the result of on-again, off-again bargaining that began last October.

And while it contained a number of provisions that officials felt were more acceptable to miners than a version rejected two weeks ago by the UMW's bargaining council, its fate hung very much in balance yesterday.

UMW spokesmen promised that the union would mount an intensive education campaign -- more intensive than the drive that brought ratification of the last contract in 1974 with less than 60 percent of the vote.

Sources said that Labor Secretary Ray Marshall and other top administration officials will publicly and repeatedly urge miners to ratify the pact.

But the difficulty of their task was underlined by dissatisfaction expressed by bargaining council members who, although bound by the UMW constitution to support the proposed contract, indicated they could not be enthusiastic salesmen. Some flatly predicted rejection of the contract.

There were these developments yesterday:

Both the UMW and the Bituminous Coal Operators Association, the industry's bargaining arm, began formal contract ratification procedures. BCOA's 130 member companies and the UMW's miners must ratify the pact before the mines are reopened.

BCOA directors will be briefed here tomorrow but the organization is not expected to announce its vote until UMW members have acted. UMW field representatives will be briefed tomorrow, then return home with copies of the contract to explain its details to rank-and-filers.

The tentative agreement gave utility executives hope, but no certainty that their fast-dwindling stocks of coal would soon be replenished, or that proposed power use curtailments in the Midwest and South would be rescinded until UMW coal again began moving.

In western Maryland, for example, the Potomac Edison Co. reported that it has less than a 23-day coal supply and plans to cut electricity production 30 percent by Thursday, as ordered by acting Gov. Blair Lee III.

"We're certainly encouraged," spokesman Don Whipp said of the proposed contract, "but what we need is coal -- not optimism."

In the coal towns of Appalachia, optomism among miners -- at least those who were talking to the press -- was in short supply.Many conceded they had yet to learn the precise details of the proposed contract, but they didn't like what they were hearing.

If it's the same as the P&M contract -- which it looks like it is -- it wen't go," said Mason Caudill, president of the largest UMW local in Tennessee. "This is our last chance and you just don't give up after this long and take something that's worse than what you went on strike with."

In Wise County, Va., miner Carl Cobb said the President's appeal to patriotism made him more suspicious. "If they give us something decent to work under, then I'm glad for the country. If they didn't, I'm sorry for the country. That's as far as my patriotism goes."

Jim Bailey, vice president of a large local at Lynch, Ky., in Harlan County, echoed that, "Usually when a President talks about patriotism it's the miners' rear that's getting picked on. It locks like all we got for 80 days of striking was a pay raise that will make us among the lowest paid skilled workers in the nation," Bailey said.

Local union leaders in Virginia, Kentucky and Tennessee were planning rallies to drum up support for rejection of the contract, even though they had not yet seen its fine print.

In western Pennsylvania, around Ford City, the reaction was similar. An estimated 150 striking miners milled around a railroad station grumbling about the contract after hearing Carter's announcement Friday.

The depot was the scene the night before of fighting between miners and Pennsylvania state troopers. Thirteen strikers were arrested after the miners apparently tried to stop a train carrying non-UMW coal.

Pressley Brandon, a miner for the Rochester and Pittsburgh Coal Co., said, "I'd go back (to work) under the money part, but I won't sign it if there's a clause in it regarding any fines or penalties for guys who go out on a wildcat strike."

There were other, more conciliatory views, however.

John Guzek, president of UMW District 6 in Ohio, said, "You can't please everybody -- especially coal miners. But this contract gives them just about all they wanted . . . You're not going to get all that you want in any negotiations."

Focal points of opposition to the contract appeared to be Kentucky, West Virginia, Ohio, western Pennsylvania and Alabama, in the view of bargaining council members.

Even though they have been without paychecks for nearly three months, strikers vow they can continue to hold out indefinitely, despite economic hardship.

In many areas, the hardship has been alleviated by food stamps and savings put together before the strike began Dec. 6. Merchants and bankers in many coal communities, following traditional practice, have extended credit to strikers to help them over the difficult spots.

In other cases, in families of several generations of miners, pensioners are sharing Social Security and federal black-lung benefits income with younger strikers. And, as in other parts of the country, a second income provided by working wives has helped keep families financially afloat.

Notwithstanding the vocal protests, the proposed contract does contain a number of provisions accepted by the recalcitrant BCOA after the union's bargaining council voted down the earlier proposal.

During the tense two weeks after the White House began applying pressure to the negotiators, UMW bargainers hammered out a number of changes designed to make the contract more palatable to the rank and file.

The industry dropped its demands for Sunday work shifts, probationary duty for new miners, certain incentives for increased production, blanket discipline of all wildcat strikers and fines for absenteeism, among other key points.

BCOA negotiators accepted UMW demands that health benefits be guaranteed, although the union acceded to an approach that would end the cost-free medical care program the UMW has had since 1950. The proposal calls for miners and pensioners to pay part of the cost of their health care. Many staunch unionists see the BCOA attack on the health program as part of an industry move to break the UMW by removing a central rallying point for national solidarity -- the fund that heretofore has been financed by assessment of tonnage royalties on the coal operators.