Trustees for the D.C. public library system have proposed closing seven neighborhood libraries and ending Sunday hours at the main library because of cuts in the library's budget, the system's director said yesterday.

The proposed closings, which amount to more than one-fourth of the District's public libraries, would be phased in beginning later this year, said Hardy R. Franklin Sr., director of the District of Columbia Public Library.

After Dec. 31, the Martin Luther King Jr. Library, the main branch at 901 G St. NW, would no longer be open from 1 to 5 p.m. on Sundays, Franklin said.

The proposed cuts were in response to an executive order by Mayor Marion Barry two weeks ago, ordering all city agencies to restrict expenditures in fiscal 1991 to fiscal 1990 levels. The mayor is expected to formally submit those cuts to the D.C. Council in several weeks, when he submits a supplemental budget for fiscal 1991, which ends next Sept. 30.

Starting next week, the mayor's office will examine the proposed cuts of the library system and all other city agencies. Barry or the council can overrule the library trustees' action.

The District government's budget office notified the library system that it had to cut $2.15 million from this year's $20.3 million budget. The trustees' vote to close the seven branches came on Tuesday, following recommendations from the library system's administration.

Franklin said no decisions have been made about which branches would be closed, but he said that each of the city's eight wards would keep at least one library.

In addition to the branch closings and abbreviated hours at the main library, Franklin said, the library system would be under a one-year hiring freeze. Workers would be furloughed for 11 days, and the system would virtually eliminate programs with D.C. schools.

Franklin said such drastic moves were necessary because 75 percent of the library's budget is for personnel. Officials are limited in the ways they can lay off workers. "We hate to do this, but we don't have much choice," Franklin said.

Library supporters are highly critical of the proposed cuts, saying that the library system accounts for less than 1 percent of the city's budget but is being forced to cut its budget by 10 percent.

"When you look at the percentage of libraries that will close, it is just heartbreaking," said Lillian Wesley, president of the Federation of Friends of D.C. Libraries, a citizens support and lobbying group. "We're always fighting to cover up another hole in the budget. But I'm not sure how much we can do here."

Under the library system's proposal, more than $800,000 would be saved through the branch closings and the hiring freeze. The 11-day furlough would save more than $500,000. Planned increases in programs and improvements such as replacing the 18-year-old carpeting at the Martin Luther King Jr. main branch would be scrapped, saving an additional $505,000. Ending Sunday hours at the King Library would save $60,000. The $100,000 new acquisitions budget would be cut in half. And the system would still have to save more than $230,000 in utility costs to meet the mayor's budget reduction order.

At least 70 employees -- about the average number who leave the system each year -- would have to retire, quit or be fired in order to meet the goal, Franklin said.

Franklin said that one branch, regional or community library would remain open in each ward, under the trustees' proposal. For example, the Mount Pleasant Branch Library, the only one in Ward 1, would be spared.

Ward 2, which has four neighborhood libraries and the main library, and Ward 3, with two regional and three branch libraries, could be among the hardest hit. The other wards each have three neighborhood libraries.

Last year, Barry cut the library's budget by $779,000. The trustees tried to block the move by going to D.C. Superior Court, but a year ago a judge gave the Barry administration the power to make the cuts, rejecting an argument by the library system's trustees that they alone controlled its finances.