Ford Motor Co. has unveiled a curvy, more fuel-efficient Focus as the replacement for its boxier Escort, Ford's most successful model ever.

Ford said the Focus will become its new entry-level vehicle at the budget end of its lineup, with production set to begin in September in Britain and later in the year elsewhere in Europe. It is to be sold in the United States in the fall of 1999, said Jacques Nasser, president of Ford's automotive operations.The Focus, featuring "stretched long curves," boasts more legroom and headroom in both front and back seats than the Escort but is a lighter car, resulting in a 25 percent gain in fuel economy. The new design should save Ford $1,000 a car in production costs in the United States, the automaker said.

The Escort, with 20 million cars sold worldwide, will continue to be available for another two years, said Nasser.

Introduced in 1980, the Escort the best-selling car in 1982, '85, '87 and '88 in the United States and finished in sixth place in 1997.