NEW YORK — Bank of America, struggling to handle mortgage refinancing after a U.S. program boosted demand, is telling some customers to wait 90 days before starting an application, said two people with knowledge of the policy.

The firm began a reservation system last week that asks those who call during high-volume times if they wish to be contacted again in 60 to 90 days, said two people who requested anonymity because the measure hasn't been announced. Wells Fargo and JPMorgan Chase, the biggest U.S. mortgage lenders, said they aren't stalling customers.

The delays may push borrowers to other lenders or discourage them from taking advantage of record low interest rates. The government's Home Affordable Refinance Program, which helps homeowners lower payments, has increased refinance applications and strained capacity at Bank of America, which exited some mortgage lines last year. The federal program, now dubbed HARP 2, was broadened in 2011 so more people qualify.

"The HARP 2 program is a much bigger deal than people thought, and Bank of America is dysfunctional to begin with," said Paul Miller, an analyst at FBR Capital Markets. "This is a result of getting out of the business at the exact time they should be getting into the business."

Customers with Bank of America checking accounts or who apply at a branch aren't subject to the delay, said one person.

President Obama made jolting the housing market from its doldrums a focus of his State of the Union address last month, when he proposed a separate program to help more borrowers take advantage of low interest rates. The proposal would let homeowners who are current on their payments save $3,000 a year through refinancing into lower-interest loans guaranteed by the Federal Housing Administration.

Chief Executive Officer Brian Moynihan told employees last month he was proud the firm stuck with clients during the tumult of 2011, when it sold assets to repair the balance sheet.

"What we didn't do is what a lot of people are doing around the world, which is walk away from their customers," Moynihan, 52, said during a Jan. 19 staff meeting.

The move is the latest by Bank of America, once the biggest mortgage lender and now No. 4, to prioritize whom it serves as the firm scales back mortgage operations. Last month, the company suspended refinancings that allowed homeowners to extract cash from their properties. BofA policies may be reversed if demand falls or as more employees are added, one person said.

"We've had strong demand, especially from the implementation of HARP 2, and we're working hard to satisfy that demand as capably as we can," said Terry Francisco, a BofA spokesman.

Bank of America lost about three-quarters of its market share in U.S. home mortgages since 2007 while grappling with defective loans inherited from its acquisition of Countrywide Financial, falling to 5.6 percent of originations in the fourth quarter, according to Miller. Refinancing makes up about 80 percent of all mortgage lending in the U.S., he said.

Wells Fargo, the nation's largest mortgage lender, hasn't limited refinance applications or discouraged borrowers, according to Franklin Codel, head of mortgage production.

"We are open for business," Codel said. "We have not constrained inflows in any way."

JPMorgan, the second-biggest mortgage lender, also isn't experiencing delays, spokeswoman Kristin Lemkau said in an email.

No. 3 Citigroup is "experiencing longer hold times but we continue to serve our customers with refinance opportunities," said Mark Rodgers, a spokesman for the bank.

Last year, BofA asked the Federal Housing Finance Agency, the overseer to Fannie Mae and Freddie Mac, to change parts of the HARP program that the firm deemed difficult to implement. HARP, which started in 2009, covers loans guaranteed by the two government-supported firms.

Obama urged changes to the program for borrowers with little or no home equity to spur more refinancing and help boost the economy. HARP has helped less than a quarter of the 4 million to 5 million borrowers projected when the program was announced in February 2009, and delays may restrict the push to bolster housing and consumer spending.