Members of the Coalition for the Homeless yesterday urged Mayor Marion Barry to scrap a plan to close the Blair and Pierce shelters for homeless men for the summer, warning that a large number of aged and mentally retarded persons would be forced onto the streets with no place to go.

"There would be a crisis and an increase in misery for these men," said Tim Siegel, a spokesman for the group. "These shelters are essential to meeting the minimal needs of homeless men."

The two Northeast Washington shelters, which are operated for the Department of Human Services by the Metropolitan Washington Council of Churches, contain 300 beds, or more than half the beds available for homeless men in the city.

City budget experts this year proposed closing the two facilities for the summer to offset rising costs of sheltering homeless families. However, the administration began to back down from that position about a month ago, and officials say efforts are under way to raise sufficient public and private funds to keep Blair and Pierce open year round.

"I'm certain that the shelters will remain open this summer," said Audrey Rowe, the D.C. commissioner of social services. "The mayor said he was committed to keeping them open if he could get private help to do it."

The Bundy Shelter, another city-operated facility for men containing 90 beds, was closed March 21, leaving 545 beds to serve a homeless male population that the coalition says exceeds 1,000.

Siegel and 10 other members of the Coalition for the Homeless, a group of local activists and clergymen organized 18 months ago, delivered petitions to Barry's fifth-floor District Building office yesterday morning, urging that the shelters be kept open.

Organizers said that 3,500 District residents signed the petitions.