Harvard and its janitors union reached a contract settlement late last night that would pay all janitors at least $11.35 an hour and raise wages steadily over the next three years. Both sides claimed success as last night’s agreement brought six weeks of heated negotiations to a close.

The settlement gives janitors slightly more than the base wage suggested by the Harvard Committee on Employment and Contracting Policies, which recommended this winter that Harvard’s lowest-paid workers earn at least $10.83 to $11.30 an hour.

Retroactive to May 2001, starting hourly wages would be $11.35, and janitors who have worked at Harvard for at least three years would earn $11.50 an hour, negotiators for both sides confirmed.

And according to the agreement, wages would increase over each of the next three years so that, by October 2005, all janitors would receive at least $13.50 an hour.

Harvard negotiators called the contract a “great agreement” that was “favorable to the workers and the University,” and union officials and janitors said the agreement was “a joyful moment” after weeks of little progress on wages.

“Everybody feels so good,” said Rocio Saenz, deputy trustee for Service Employees International Union Local 254 (SEIU), which represents Harvard janitors. “Harvard is taking a great step on workers’ rights.”

The agreement, which already has the blessing of the University’s central administration, will likely be ratified by the SEIU’s full membership tomorrow, union officials said.

In addition to the higher wage levels, Harvard agreed to a union proposal that offers health care without worker co-payments, using a fund paid for by Harvard and administered by the union. The agreement also includes a “parity” provision: the University will require contractors to pay outsourced workers wages and benefits that, in total, are comparable to what Harvard pays its own workers.

Yesterday’s agreement came on the heels of an escalation in protest tactics by SEIU and students in Harvard’s Progressive Student Labor Movement (PSLM). Nine students, workers and labor officials were arrested by police Tuesday afternoon during a protest after they blocked traffic on Mass. Ave. in front of the Holyoke Center, which is home to Harvard’s Office of Labor and Employee Relations.

Both sides agreed that Tuesday’s protests were a turning point in the contract talks, but each maintained that the opposite side had given in to pressure.

Lead Harvard negotiator David A. Jones said press accounts had downplayed the Tuesday arrests, and he maintained that, disappointed by press coverage, the union had decided to make compromises.

“If [the protest] had been viewed by the union as more successful, we probably wouldn’t have seen as much movement,” Jones said early yesterday evening. “People, including the media, are starting to take notice of how unreasonable the union’s [initial] requests were going to be.”

But PSLM members and workers said the arrests, which were televised that night by several local news outlets, had harmed Harvard’s public image and led to the progress today.

Janitor Frank Morley, one of those arrested Tuesday, said Harvard officials had been watching the protest and had seen that the union “meant business.”

SEIU organizer Jairo Dias said he was “100 percent sure” the arrests had prompted Harvard’s movement at the bargaining table, because “they could realize the next step would be worse.”