Newspaper unions and a potential buyer of the Daily News remained stalemated as a deadline loomed on concessions to determine the fate of the nation's largest general interest daily.

Both the unions and Allbritton Communications Co. said there had been no contact between the two parties since financier Joe L. Allbritton broke off talks Thursday. No new meetings were scheduled.

Allbritton had set a deadline of midnight today to complete any bargaining with the News unions. According to an agreement with the News' owner, the Tribune Co. of Chicago, he would have until April 30 to negotiate purchase of the paper after obtaining union concessions. A spokesman for the Allbritton company, Larry Friedman, said he would not speculate whether Allbritton's interest in the News will continue past tonight's deadline.

Talks broke off after the unions refused Allbritton's demand for a two-year wage freeze and a five-year, no-strike contract. Theodore Kheel, adviser to 10 News unions, said the unions were willing to negotiate "at a moment's notice."

Meanwhile, in Dayton, Ohio, two large daily newspapers, the Dayton Daily News and the Journal Herald, are combining reporting staffs in a reorganization to keep them off the growing list of failed or struggling newspapers, management says. Ninety employes will be laid off.