Yale negotiators offered a new pension proposal during bargaining with the University’s two largest unions Monday, prompting criticism and a counteroffer by union leaders shortly after.

Yale spokesman Tom Conroy said the University does not have plans to respond to the unions’ move. Conroy said the union proposal would cost about $25 million more than Yale’s proposal — a cost the University can afford, union leaders said.

Retirees currently receive pensions as a fixed amount of money on a monthly basis. Pension calculations involve a formula that takes into account years of service, salary at age of retirement and a fixed multiplier that is agreed upon during contract talks.

The two sides have clashed over proposed increases in the pension multiplier during the latest round of negotiations. Union leaders have said that pensions are a particularly important issue this year because approximately 20 percent of union members plan to retire before the new contracts expire.

The University’s modified proposal, the first made since its original offer in June, increases the pension multiplier.

Union leaders responded with a counteroffer hours later, decreasing their proposal for the pension multiplier by 0.15 percent, the same increment by which Yale moved its offer.

The University and locals 34 and 35 have been negotiating new contracts for nearly 4,000 workers since February. Contract talks stalled at the end of last year, and the two sides did not negotiate for nearly three months. Negotiators held three full-table bargaining sessions this month and have scheduled daily negotiations through Jan. 23.

Locals 34 and 35 represent Yale’s clerical, technical, service and maintenance workers.

Conroy said the University’s proposals have been more realistic than those the unions have presented.

“We began bargaining this year with a significant proposal to increase pensions,” he said. “Today, we enriched what was already a very attractive proposal.”

Local 35 President Bob Proto said he does not believe the University’s new pension proposal is adequate.

“We thought the University was going to do something a little more significant,” he said. “We’re at a place now where we’re starting to see that they don’t respect the workers enough to come in with a decent pension proposal.”

During these contract talks, the two sides have made proposals in increases to the pension multiplier that would bear very different costs.

Conroy said the unions’ proposal is roughly $25 million more expensive per year than the University’s offer. Proto said the pension plan is overfunded and that Yale would have no problem funding the unions’ proposal.

Negotiators have scheduled three more bargaining sessions this week. At today’s session, the two sides do not have plans to discuss pensions and will instead be talking about training for employees.