NEW YORK - U.S. home prices slipped in November and were softer than expected in the latest sign that a rebound in the U.S. housing market is tenuous, according to Standard & Poor's/Case-Shiller indexes on Tuesday.

The S&P composite index of home prices in 20 metropolitan areas slipped 0.2 percent in November after a revised 0.1 percent October dip, for a 5.3 percent annual drop.

A Reuters survey had forecast a 0.1 percent November rise. Prices were originally reported as unchanged in October.

On a seasonally adjusted basis, the 20-city index rose 0.2 percent in November, S&P said, after a 0.3 percent rise the prior month.

The home price picture remains mixed despite steady annual improvement, said David M. Blitzer, Chairman of the Index Committee at Standard & Poor's.

Only five of the markets saw price increases in November versus October, he said. What is more interesting is that four of the markets -- Charlotte, Las Vegas, Seattle and Tampa -- posted new low index levels as measured by the past four years.

Other markets continue to improve month over month, with Los Angeles, Phoenix, San Diego and San Francisco posting price rises for at least six consecutive months.

(Reporting by Lynn Adler; Editing by James Dalgleish)