Mayor Marion Barry yesterday proposed spending $125,000 to keep the District of Columbia's public swimming pools open for an additional nine days this summer and another $125,000 to provide more staff workers and better maintenance at recreation centers.

Barry's proposal, which must be considered by the City Council, would extend the swimming season from the scheduled pool closings on Saturday, Aug. 28 through Labor Day, Sept. 6.

Barry said he rejected a proposal to open the pools on Memorial Day weekend rather than the scheduled June 21 because of uncertain weather conditions and an expected infrequent use of the pools before the end of the school year on June 18.

Barry's plan is to use money authorized for salaries that will not be disbursed for that purpose to provide $125,000 for the operation of the swimming pools from Aug. 28 until Sept. 6, and $17,300 for supplies and maintenance and $107,700 to hire 52 additional staff members for the recreation centers.

The plan is similar to a proposal made last week by council member Betty Ann Kane (D-At Large), who is running for mayor in the Sept. 14 Democratic primary. Kane's plan, which included weekend operations of the pools beginning Memorial Day, was voted down in what several council members considered a political rebuff to give the mayor time to present his own proposal.

Dr. William Rumsey, director of the Recreation Department, said yesterday that he expected the council to approve Barry's request.