Contracts to buy previously owned homes fell unexpectedly in November, the National Association of Realtors said on Friday, the latest sign of weakness in the U.S. housing market.

The NAR's pending home sales index decreased 0.7 percent from the prior month to 101.4. October's index was unrevised.

Economists polled by Reuters had forecast pending home sales to rise 0.7 percent last month.

Pending home contracts are seen as a forward-looking indicator of the health of the housing market because they become sales one to two months later.

Compared to one year ago, pending sales were down 7.7 percent in November, the eleventh straight year-over-year drop.