A nationwide coal strike in less than two weeks became virtually assured yesterday as contract talks between the industry and the United Mine Workers collapsed in a flurry of bitterness.

Faced with a Dec. 6 contract expiration deadline, negotiators met for less than two hours, remained at loggerheads and then quit with no date set for resuming.

Afterward UMW president Arnold Miller and spokesmen for the Bituminous Coal Operators Association traded angry countercharges of badfaith bargaining.

Miller said that "absolutely no progress" was made in the latest session and that, as a result, "a strike on Dec. 6 appears to be inevitable."

The contract, which would require at least 10 days to go through the ratification proces, covers some 130,000 UMW miners who produce slightly more than half of the nation's coal.

Industry and labor spokesmen have warned repeatedly that a strike seemed probable, but Miller's statement yesterday was his strongest yet.

The BCOA negotiators "repeatedly threatened" the UMW representatives yesterday, calling the union "weak and divided" and saying that the UMW was "on probation," Miller said.

Although details were sparse, Miller's statement indicated that the BCOA has made a proposal that would, in effect, end the tonnage-royalty system now used to provide extensive health benefits to miners and their families.

The UMW president said the industry negotiators were refusing to restore health benefits that were cut on July 1 after a wave of wildcat strikes.

Instead, Miller continued, the BCOA proposed "a reduced program through company insurance plans" - a sharp departure from the present system, which is funded on tonnage and work-time formulas.

Miller also reported that the industry is proposing a new no-strike clause that would penalize wildcatters by reducing their wages.

Both issues - the health program and the right to strike - are vital. The health care covers some 800,000 beneficiaries, mostly in remote communities in the Eastern coalfields.

The cutbacks in July touched off a further wave of wildcats that did not end until Labor Day, leaving the health fund even more depleted.

Miller has insisted that losses suffered by the health program be restored by the operators in the current contract negotiations.

In demanding a limited right to strike over grievances on a local basis, the miners argue that it would serve both sides by putting an end to the wildcat walkouts and allow quick settlement of local disputes.

A BCOA statement issued after the collapse of the talks yesterday laid the burden on the UMW, saying "it seemed clear the union had a breakoff in mind from the time the meeting started."

The operators said they had been prepared to continue meeting through the weekend. Miller indicated he would return to the talks only when the BCOA is ready to carry on "in good faith."

While a strike on Dec. 6 would mean that all UMW families would lose medical benefits for the duration and pensioners' monthly payments would be reduced, an immediate impact on coal supplies would not be felt.

Stockpiles by electrical utilities and other industries in anticipation of a UMW strike, in addition to a growing amount of coal from non-UMW mines, would be available.