The Washington Star canceled yesterday a scheduled meeting with 10 unions and federal mediators amid a flurry of rumors that Star owner Joe L. Allbritton was about to sell the newspaper.

Those rumors were further fueled by news that Michigan publisher John P. McGoff had agreed to purchase a Capitol Hill town house. McGoff, owner of about 80 daily and weekly newspapers, has long indicated an interest in buying the Star.

Reached at his home in Michigan yesterday, McGoff said he had verbally agreed to buy the house at 331 Maryland Ave. NE for $89,000 from the Washington correspondent of his Panax newspaper chain.

Only last week, the correspondent, Thomas H. Ochiltree bought the house from former Star reporters, Robert Walters and his wife Martha Angle. The sale was handled by Ochiltree's wife, Jewel, a local real estate salesperson.

MCGoff, who left Wahington for Michigan yesterday morning, said he did not know whether the Star was now for sale, and added that he had not spoken to Allbritton for a long time.

McGoff said he was "well along" in negotiations to purchase an unnamed daily newspaper somewhere "north of Washington." He added that he was not currently negotiating for the Star.

Asked whether his other prospective purchase ruled out his interest in the Star, McGoff said, "I'm never fully occupied."

Allbritton, who returned to Washington today after attending board meetings on the West Coast, did not return several phone calls to his office, but Star executives and industry sources said they had no knowledge of an impending sale.

Neil Travis, an aide to Australian publisher Rupert Murdoch, who recently bought the New York Post and New York magazine, said yesterday, "There is no way" Murdoch would be buying the Star.

Rumors of spending sale surfaced on Monday when Allbritton ordered his name and designation as publisher removed from the Star's editorial page masthead.

According to Star columnist Mary McGrory, an explanation of that will appear in today's (Friday's) editions of the Star. McGrory said Allbritton told her that his role at the paper was financia land that he would retain the title of chairman of the board, which he said he believed was more appropriate to his function than the title of publisher.

Allbritton has also applied to change the call letters of WMAL-TV, which he also owns, incorporating his initials, to WJAL-TV.

Some labor and industry sources have suggested that both the disappearance of Allbritton's name from the editorial page and the new call letters for WMAL-TV are part of a campaign to frighten unions at the Star by suggesting that Allbritton might sell the financially troubled newspaper and retain the profitable television station.

The Star is offering the unions a monet package totaling $35 a week over three years with none of it during 1977. The package includes fringe benefits as well as wages.

The unions have hired an independent auditor to assess the Star's financial position and the auditor's report is expected to be available today.

Ochiltree said that McGoff planned to use the Capitol Hill town house he is buying as a place to stay on his fairly frequent visits to Washington. However, McGoff later said that he has no intention of living in the three-storey residence and considers it a real estate investment.

Mrs. Ochiltree said the $89,000 house purchase "is probably the smallest investment ever made by the wealthy, conservative Michigan publisher.