Contracts to buy previously owned U.S. homes fell for a fifth straight month in October, hitting a 10-month low and adding to signs of cooling in the housing market.

The National Association of Realtors said on Monday its Pending Home Sales Index, based on contracts signed last month, slipped 0.6 percent to 102.1, the lowest level since last December.

Contracts were 1.6 percent below last October's levels.

Economists polled by Reuters had expected signed contracts, which become sales after a month or two, to rise 1.3 percent.

The Realtors group said a 16-day partial shutdown of the federal government last month had sidelined some potential buyers.

"In a survey, 17 percent of realtors reported delays in October, mostly from waiting for IRS income verification for mortgage approval," said NAR chief economist Lawrence Yun in a statement.

The report was the latest indication of a moderation in the housing market recovery. A report from the Realtors group last week showed home resales also fell in October.

Sales have been dampened by a rise in mortgage rates.