WASHINGTON -- U.S. homeownership fell to a 20-year low in the fourth quarter as more Americans opted to rent rather than buy a house, government data showed on Thursday.

The seasonally adjusted home ownership rate slipped to 63.9 percent, the lowest since the third quarter of 1994, the Commerce Department said. The rate, which peaked at 69.4 percent in 2004, was 64.3 percent in the third quarter.

The residential rental vacancy rate dropped four-tenths of a percentage point to 7.0 percent in the fourth quarter.