This time, is The Times of London about to close for the last time?

The Times of London and its stablemate the Sunday Times again stand on the brink of closure.

The future of both newspapers, nowadays owned by the Australian magnate Rupert Murdoch, is once more a potent issue in British politics.

The latest crisis arises from two intertwined problems:

* Mr. Murdoch, wrestling to make the papers profitable, has demanded 600 layoffs -- and says he will shut The Times and Sunday Times down if he does not get them.

* At the same time, Mr. Murdoch has generated a lively dispute by quietly transfering the ownership of the titles of the two papers from Times Newspapers Ltd. to the Murdoch parent company News International Ltd.

When it was discovered that this was done without consulting five independent directors appointed last year as watchdogs of the newspaper's interests, there was an immediate call to the British government to halt the transfer.

Last week Mr. Murdoch was forced to return the titles to Times Newspapers Ltd. -- amid claims that the original transfer had been part of a clandestine attempt to shut down both papers and then reopen them on an entirely different manning basis.

Mr. Murdoch angrily denied any such intention, but the government's decision to force his hand appears to have persuaded him to adopt an even tougher stand over lay-off talks.

There is no doubt that something drastic must be done if the newspapers are to be returned to profitability.

The Times under its editor, Harold Evans, has been steadily increasing circulation, but losing about (STR)15 million per year ($27 million) through excessive manning and other wasteful practices.

Of the 600 layoffs being demanded, the bulk involve printing and clerical staff. Mr. Murdoch wants a slimmed down operation so that huge wage and salary overheads no longer undermine attempts to boost the circulation of the two papers.

Trade union leaders asked to cooperate say Mr. Murdoch does not want to negotiate. He is, they claim, demanding a fait accompli and has told them that if he does not get his way, the two papers will close.

Throughout last week attempts to negotiate a compromise got nowhere. The original deadline for these talks was to be Feb. 22 but such slippage on this seemed possible at time of writing.

Meanwhile, morale at The Times and Sunday Times has slumped, with many journalists deciding to leave now and obtain unemployment compensation rather than await the paper's collapse and perhaps get little or no compensation at all.

Mr. Murdoch now plans to try to pursuade the five directors to accept that a titles transfer would be useful. Some believe Mr. Murdoch may be planning an entirely new publishing operation, using nonunion labor. Such a move however would hit snags, including a probable refusal by truck and train union members to move The Times and Sunday Times around the country.

According to Mr. Murdoch, the negotiating atmosphere is bleak. That is the view of union spokesmen too. It looks as though The Times and Sunday Times, which were shut down for nearly 12 months only two years ago, are in for another protracted period of closure.

The problem is that this time even the optimists are beginning to believe the closure may be forever.