An 18-year library tradition will come to an end on Friday when Widener Library holds the last of its monthly book sales.

"We're really in the planning stages of how we're going to continue the sales," said Beth S. Brainard, communications and public information officer for the Harvard College Library. "We want to make sure people can buy the books."

Library officials said the monthly sales will probably be replaced with once-a-semester sales at Hilles Library.

The Gifts and Exchange Division of the library system, which coordinates the sales, will also be relocated to Hilles.

The space allotted to the division in Widener is needed for other purposes during renovations that are scheduled to begin in June, library officials said.

But some library employees and book sale regulars are not making the move without a fight.

Staff members are circulating petitions demanding that the book sale be continued during the renovation and that it remain in Widener.

"We've handed in 200 signatures already and we're continuing," said Karen O'Brien, a library assistant at Widener who is also one of the coordinators of the petition drive.

"A lot of grad students and professors... take advantage of the book sale and they're really upset about this," O'Brien said.

Some library employees said moving the sale to Hilles will make the event less accessible.

"I don't think the people will come. Hilles is a faraway place," said a long-time library employee, who asked not to be named "Harvard Square is very popular and that's what draws people into Widener."

"People walk out there with four or five boxes of books. How are they going to do that at Hilles?" the employee added.

O'Brien said the College could hold the sales in Pusey Library or another nearby location during the renovation.

Employees of the division believe their jobs are less secure at the new location, according to O'Brien, who is representing their grievance on behalf of Harvard Union of Clerical and Technical Workers.

"They think their job is going to be fully phased out and their duties portioned off to other people," she said.