With the closing of Bob Slate Stationer, the owners of this Church Street building in Harvard Square would have two spaces to fill. The Harvard Square Cafe shut its doors months ago.

Potential buyers have come forward for the venerable Bob Slate Stationer stores in Porter and Harvard squares, sales agent Walter Huskins said Monday.

Closing the business, which has been in Cambridge for 78 years, has been called a tragedy by customers, but the brothers running the three sites have been trying to sell to “the right buyer” since October 2009 without success. The Boston Globe reported late last week that Justin and Mallory Slate talked with four potential buyers in that time but that they deemed the bidders “inadequate” to take care of the business and its 29 employees.

Reports of the closing, first in Cambridge Day and then in the Globe, brought forward two people over the weekend “interested in riding in as white knights,” Huskins said from the offices of Ridge Hill Partners Inc. in Needham.

“We’re getting them the necessary information,” Huskins said, including a price he wouldn’t disclose and details about the stores, each of which are about 2,500 square feet but only one of which, the one at 1975 Massachusetts Ave., is owned by the brothers. A possible complication is that the two Harvard Square stores, at 63 Church St. and 1288 Massachusetts Ave., have expired leases and landlords already looking for replacement tenants.

Harvard Square real estate can move slowly, though. The Lee’s Sandwich Shop space, next door to a Bob Slate’s at 61 Church St., remains unoccupied even though the sandwich shop (later called the Harvard Square Cafe) has been closed for months.

The drop-dead date for a Bob Slate’s deal is still several weeks away though, on March 21. That’s when the doors will close for the last time, Huskins said.

In the meantime, a close-out sale begins in about two weeks, the Globe said.