New foreclosure data show that banks are increasingly placing homes with unpaid mortgages on a countdown that could deliver a swell of new foreclosed properties onto the market next year.

Foreclosure listing service RealtyTrac Inc. says the number of U.S. homes entering the foreclosure process for the first time increased on an annual basis for the second month in a row in June.

The increase comes as banks step up action against borrowers to tackle a backlog of mortgages behind in payments.

The trend could end up creating a wave of bank-owned properties that would likely hit the market, but not before next year.

RealtyTrac notes that it took an average of 378 days for a U.S. home to complete the foreclosure process in the second quarter.