FRESNO, Calif. -

Federal regulators have rejected California's request to exempt a route in the Central Valley for what would be the nation's first bullet train from a lengthy planning review.

The three-member Surface Transportation Board's decision Wednesday could force a delay in designing and building a five-mile stretch of the route in Fresno. However, a spokeswoman for the California High-Speed Rail Authority said no delays were anticipated.

The federal board approved the Merced-Fresno portion of the rail line earlier this year and state officials awarded a contract for its first 29-mile construction segment.

A Sacramento County judge last week rejected a request from the rail authority to sell $8 billion in voter-approved bonds.

The $68 billion project would run trains from Los Angeles to San Francisco by about 2028.