Khristopher J. Brooks St. Mark’s Bookshop at 31 Third Avenue.

The co-owners of one of the neighborhood’s most popular bookstores pleaded to members of Community Board 3 last night for help as they struggle to stay in business.

The causes of the St. Mark’s Bookshop’s financial woes (a book industry in free-fall amid the rise of e-readers and online retailers) have been well documented. Things became so dire that the owners even posted an ominous note in the store entrance, saying “Find it here, buy it here, keep us here.”

Now, the store’s owners are pressing their landlord, Cooper Union, to reduce the $20,000-per-month rent for the space in the base of the dormitory building at Third Avenue and Stuyvesant Street.

“The economy crashed, business declined more and more, and the rent has become very burdensome,” said Terence McCoy, 67, one of the owners of the shop that is in the third year of a 10-year lease. “All our 40-hour employees are now working 24-hour weeks. We laid off a lot of part-time people.”

The shop’s rent, according to one Community Board member, Bob Zuckerman, is market rate. Nevertheless, the Economic Development Committee voted unanimously 9-0 to endorse the owners’ efforts to have it reduced, saying the 33-year-old shop constituted a “special case” because of its value to the neighborhood.

Councilwoman Rosie Mendez shared the board’s affinity for the store.

Khristopher J. Brooks A sign taped to the front of the bookshop.

“A significant rent concession by Cooper Union could save this irreplaceable neighborhood institution,” wrote Ms. Mendez in a letter to the Cooper Union vice president that was read at the meeting. “Given the breadth of Cooper Union’s real estate investments, including the soon-to-be redeveloped 51 Astor Place as a fully commercial building, I believe that a rent concession to St. Mark’s Bookshop would not constitute a large burden.”

Three other locals circulated a petition and expressed a strong displeasure with Cooper Union for not having already accommodated the ailing shop.

“How truly despicable it is that an institution that gets so much from this city and — considering we are talking tax dollars — from its residents, should show no generosity to another longtime beloved and now endangered institution,” wrote Marilyn Appleberg, the president of the 10th and Stuyvesant Streets Block Association, in another letter read at the meeting.

Lisa Kaplan, a spokeswoman for Ms. Mendez, said that the councilwoman had met with Cooper Union administrators earlier this week regarding the bookshop. A meeting between the store’s owners and Cooper Union officials is planned for next week, as well.

A spokeswoman for Cooper Union would not comment on the ongoing discussions.

Mr. McCoy said that he and co-owner Bob Contant were facing a “very difficult” situation.

“We make more from social security checks than from the store,” Mr. McCoy said. “We just want to keep it open.”