Union photoengravers at the Washington Star voted yesterday to reject a contract proposal under which they would have received no increase in pay or fringe benefits this year. The vote came shortly after editorial and commercial employees voted to accept a similar proposal.

The proposed 3-year contract provides a $20-a-week increase in pay and fringe benefits in 1978 and 1979.

Joe L. Allbritton, chairman of the board of the Star, had reportedly told the unions he would allocate no more money to purchase newsprint until the contracts were signed. According to a labor source, the Star has only a few day's supply of newsprint on hand. Newsprint is the paper on which newspapers are printed.

Officials of the Star could not be reached for comment last night.

The editorial and commercial employees, represented by the Washington-Baltimore Newspaper Guild, voted yesterday to adopt a resolution asserting that the new contract proposal was accepted by the margin of one vote.

The vote by which the resolution was adopted was not recorded. Details of the photoengravers' vote could not be immediately learned.

Seven other unions at The Star have already accepted terms similar to those offered to the photoengravers and to the editiorial and commercial employees.

The union representing pressmen at the financially troubled paper has reached a tentative agreement with the company. It will be submitted to the union members of a ratification vote in about 10 days.

Negotiations between The Star and the unions have been held in an atmosphere of tension heightened by recurring rumours that Allbritton was planning to sell the newspaper. The Star's current losses have been estimated by industry sources at about $500,000 a month.

In order to comply with regulations of the Federal Communications Commission, Allbritton is now obliged to dispose of either The Star of WMal-TV, a highly profitable television station.

Washington Star Communications, Inc., parent company of the newspaper, concluded a transaction yesterday, transferring ownership of radio stations WMAL-AM and WMAL-FM to the American Broadcasting Companies, Inc., for about $16 million.

The sale of the stations figured in the effort to insure compliance with FCC regulations.