New York publisher Rupert Murdoch delivered another jolt to the city's two strike-bound morning papers yesterday with word that he will break into their market next week with a 10-cent tabloid.

The Australian press baron's latest publishing venture will be known as The Daily Sun and will be published Monday through Saturday, probably starging next Tuesday morning, according to Murdoch aides.

"It will be a bright, entertaining, street-smart paper, not unlike what The Daily News was like '75 years ago," said Neal Travis, a top Murdoch lieutenant who will serve as editor of the new paper.

Both The Times and News are morning dailies selling for 20 cents a copy, but The Daily Sun is expected to compete most directly with The News, also a tabloid. The Post , which Murdoch acquired two years ago, is the city's only major afternoon newspaper.

Murdoch's announcement came less than two weeks after he broke with publishers of the other two papers by making a separate settlement with striking pressmen. He has been reveling in a publishing vacuum ever since as talks between the other papers and the pressmen failed to produce a city-wide contract. The Times-Daily News strike is in its 11th week.

"It is essential that we take advantage of this opportunity to widen our revenue base," said Murdoch in a memo to the Post staff yesterday afternoon.

Meanwhile, talks between the pressmen's union and the other papers were recessed when union president William Kennedy left to meet with Post officials to discuss the new tabloid. Sources said a contract for the new paper was worked out within hours.

Travis, who has worked for Murdoch's Post and New York Magazine and was instrumental in organizing the new paper, said he anticipates a six-day-a-week paper with an initial press run of up to 750,000.

He said it will be published in the Post's plant, using the presses when they are finished printing the Post. The rest of the operation will be separate, including an editorial staff of about 75 persons, mostly from the Post, Travis added.

The Post was third in size and financial strength among the three dailies before the strike, printing about 625,000 copies six days a week. Since it resumed publication Oct. 5, it has grown to nearly 1 million copies a day and added a Sunday paper, which this week ran to 350 pages.

Martin Fischbein, an assistant to Murdoch, said the new paper will spend $5 million to $10 million to radio and television advertising to introduce itself.

Deaths are more commone than births among big city newspapers, but Murdoch, with about 100 newspapers and magazines stretching from Australia to Great Britain, is a defier of Convention. An earlier attempt to start up a New York daily failed earlier this year when The Trib, organized by Leonard Saffir, succumbed after three months of publication and $4 million in expenses.

What effect Murdoch's new venture will have on the other papers' negotiations was unclear. On Wednesday, the publishers and the pressmen rejected a strike settlement plan offered by Theodore W. Kheel, an adviser to other newspaper craft unions, to get the pressmen back to work while an outside panel resolves the disputed issues of work rules and pressroom manning.

"We don't want someone imposing something we would not want to accept," said Walter Mattson, executive vice president of The Times, Kennedy said too many issues remain on the table and added: "We haven't resolved one issue." Talks are scheduled to resume this afternoon.