LOS ANGELES – More than 1 million American households are likely to lose their homes to foreclosure this year as lenders work their way through a huge backlog of borrowers who have fallen behind on their loans.

Nearly 528,000 homes were taken over by lenders in the first six months of the year, a rate that is on track to eclipse the more than 900,000 homes repossessed in 2009, according to data released by RealtyTrac Inc., a foreclosure listing service.

“That would be unprecedented,” said Rick Sharga, a senior vice president at RealtyTrac. comparison, lenders have historically taken over about 100,000 homes a year, Sharga said.

The pace at which more homeowners have entered the foreclosure process has slowed as banks continue to let delinquent borrowers stay longer in their homes rather than adding to the glut of foreclosed properties on the market. At the same time, lenders have stepped up repossessions in an effort to clear out the backlog of distressed inventory on their books.

The number of households facing foreclosure in the first half of the year climbed 8 percent versus the same period last year, but dropped 5 percent from the last six months of 2009, according to RealtyTrac, which tracks notices for defaults, scheduled home auctions and home repossessions.

In all, about 1.7 million homeowners received a foreclosure-related warning from January to June. That translates to one in 78 U.S. homes.

Foreclosure notices posted monthly declines in April, May and June, but Sharga said one shouldn’t read too much into that.

“The banks are really sort of controlling or managing the dial on how fast these things get processed so they can ultimately manage the inventory of distressed assets on the market,” he said.

Assuming the U.S. economy doesn’t worsen, aggravating the foreclosure crisis, Sharga projects it will take lenders through 2013 to resolve the backlog of distressed properties that they have on their books right now.