A federal district court judge here ruled nine foreign uranium producers in default today for refusing to answer charges in a price-fixing suit brought by Westinghouse Electric Corp.

The nine companies did not respond to the suit, filed Oct. 15, 1976, against 12 foreign and 17 domestic uranium producers and their agents. In its suit, Westinghouse charged the uranium suppliers violated antitrust laws by conspiring to fix supplies and prices of uranium and force middlemen such as Westinghouse out of the market.

The Pittsburgh-based company is short about 54 million pounds of uranium needed to fulfill supply contracts with 13 utilities, and is itself being sued for failure to deliver nuclear fuel. Westinghouse had settled with four of the suing utilities out of court.

Judge Prentice Marshall issued an original default judgement against the uranium producers in 1977, but the ruling today was necessary to provide enforcement of the earlier order, a court spokesman said.

Westinghouse can now seek damages against the foreign uranium producers.

As a practical matter, however, there is still some question of whether Westinghouse could recover damages from many of the foreign producers since only a few have uranium-producing properties with the United States.

The nine producers are: Anglo-American Corp., South Africa; Conzinc Riotinto, Ltd., Australia; Mary Kathleen Uranium Ltd., Australia; Nuclear Fuels Corp., South Africa; Pancontinental Mining Ltd., Australia; Queensland Mines Ltd., Australia; Rio Algon Ltd., Canada; Rio Tinto-Zinc Corp., England; and RTZ Services Ltd., England.