Mayor Marion Barry asked the D.C. City Council yesterday to approve a 3.5 percent annual pay raise for 10,700 nonunion city employes, an increase that would match those negotiated with the city's major public employe unions.

The mayor also recommended a 4 percent increase for nonunion police and fire employes, comparable to the raises negotiated with unions in those departments.

The increase would cost the city $12.7 million. Barry said funds to cover the increase were included in the city's fiscal 1986 budget, which has been approved by the council and awaits final approval by Congress.

"This action is vital to our ability to maintain the quality of the District government's work force," Barry said. "This increase assures us of pay levels which are comparable to surrounding jurisdictions and the federal government."

Most of the nonunion workers are supervisors, personnel officials, court employes and workers in other city agencies not covered by collective bargaining. The proposed raise is part of a longstanding custom of awarding them increases similar to those of unionized employes.

The proposal would also increase the D.C. government's pay ceiling by 3.5 percent to $65,930.

Barry said a survey required by city law showed that neighboring jurisdictions had granted pay increases of 4 to 4.5 percent. He said the 3.5 percent increase would keep D.C. salaries "competitive."

The District government's salaries rank highest in the region for skilled trades, laborers and some professional occupations, he said, while they rank in the middle among the region's governments in most other categories.