WASHINGTON, March 31 Reuters Contracts to buy U.S. previously owned homes fell for a second straight month in February, signaling a cooling in the housing market in the months ahead as accelerating prices amid tight supply and rising mortgage rates reduce affordability.

The National Association of Realtors NAR said on Wednesday its Pending Home Sales Index, based on contracts signed last month, tumbled 10.6 to 110.3, with contracts falling in all four regions.

Economists polled by Reuters had forecast pending home contracts, which become sales after a month or two, would decline 2.6 in February. Compared to a year ago, pending home sales slipped 0.5 in February. Contracts had increased for eight straight months on a yearonyear basis.

The decline in contracts suggested sales of previously owned homes could fall further in March after dropping sharply in February. The supply of existing homes is at a record low.

The 30year fixedrate mortgage has risen to a ninemonth high of 3.17, according to data from mortgage finance agency Freddie Mac. Though mortgage rates remain historically low, the sustained increase since February is contributing to making home ownership more expensive for firsttime buyers.

Mortgage rates have risen in tandem with U.S. Treasury yields, which have spiked in anticipation of stronger economic growth this year and higher inflation.

Data on Tuesday showed the SP CoreLogic CaseShiller house price index soared 11.2 in January from a year ago, the…