Negotiators for the United Mine Workers and the coal industry reached tentative agreement yesterday on a contract to end the 63-day coal strike, the longest in the union's history.

The ageement, which included an overall increase in wages and benefits of nearly 37 percent over the next three years, now goes before the union's 39-member bargaining council. The council's approval is necessary before a contract can be submitted to the 160,000 striking miners.

The council was sharply divided on key contract provisions that leaked out before yesterday's formal agreement, and the contract's approval at a councill meeting scheduled for this morning is not certain.

The settlement was announced by UMW President Arnold Miller, who described it in a prepared statement as "by far the best agreement negotiated in any major industry in the past two years."

The union's proposed contract with the Bituminous Coal Operators Association, the industry's bargaining group provides for a wage increase of $2.35 per hour by 1981 over the present straight-time hourly average wage of $7.80, Miller said. He also said health benefits, cut off when the strike started, will be guaranteed, and pension benefits, which ended last week, will be restored.

Miller did not mention the bargaining teams' earlier agreement to institute new disciplinary measures to control wildcat strikes, including fines against miners when they call them without management provocation. Nor did he mention that the union dopped its earlier demand for a right to strike over local grievances.

It is also understood that the contract provides for assumption by the coal companies of the financially troubled health and retirement programs, which have been administered jointly since the UMW pioneered decades ago in setting up union medical and pension plans.

Announcement of the proposed contract, negotiated under the auspices of the Federal Mediation and Conciliation Service, was delayed for about an hour by what was described as a last minute snag. Miller declined to Predict whether the bargaining council would approve the contract, but said he hoped the council would agree to submit it to the members.

Miller was joined at the press conference announcing the agreement by West Virginia Gov. John D. Rockefeller, IV, who described the tentative settlement as a "matter of great relief."

The tentative settlement came as once-huge coal stockpiles fell below 30-day levels at many electric utilities in Eastern industrial states and officials warned of possible industrial shutdowns and commerical power curtailments.

Even if the bargaining council approves the pact and the members ratify it, it could take 10 to 14 days before union coal is mined again - meaning that full production is unlikely before March. So shortages in heavily coal-independent states - including Ohio, Pennsylvania, West Virginia, Kentucky, Indiana, Illinois, Missouri and areas served by the Tennessee Valley Authority - are still likely.

The UMW normally mines one-half the nation's coal, down significantly from the heydey of John L. Lewis, but still enough so that a sufficiently long strike - especially when combined with harsh winter weather - can threaten energy supplies.

The strike became the longest in the UMW's history of tumultuous relations with the bituminous coal industry last Friday, when it surpassed the 59-day record set in 1946.

The impact was felt first and hardest among the miners themselves. All health benefits were terminated when the strike started Dec. 6, and pensions were cut off Feb. 1, though most retirees continued to receive Social Security and black-lung benefits.

The negotiators, who had been meeting in fits and starts since October, had been on the verge of settlement since Thursday, only to draw back in a dispute over final economic terms, including wages and benefits.

At the request of federal mediators, President Carter stepped in early Friday to urge the UMW to hold off a bargaining council meeting that had been scheduled for that morning - presumably to approve a contract. Miller readily agreed, giving the union negotiators more time to "sweeten" the package before facing a possibly rebellious bargaining council.

Three years ago the council twice rejected a negotiated settlement before giving its approval, and the contract was only narrowly ratified by the members even though it contained a 54 percent increase in money over three years.