The California High-Speed Rail Authority has pushed back the deadline to finish the first stages of the bullet train system in the central San Joaquin Valley.

The authority is now saying in bidding documents being considered by contractors that it has pushed back its anticipated completion date for its Madera-Bakersfield section to the end of 2017. The agency has previously said that the completion deadline was September 2017 -- a deadline linked to more than $3 billion from the federal government, including American Recovery and Reinvestment Act stimulus funds and transportation money.

"What we've recognized is that the project deadline had been tied to the ARRA deadline unnecessarily," authority CEO Jeffrey Morales said Thursday. "That would result in added acceleration costs."

Bids from would-be contractors for the first stretch of the train line, between Madera and downtown Fresno, are due by mid-January. The revised bid requests issued this week give the winning contractor 54 months from when a contract is awarded -- expected to be mid-2013 -- to complete the work. Earlier, contractors were given 42 months to finish their job.

Morales said the change now aligns the contract with a high-speed rail business plan adopted by the Rail Authority this year that called for the first segment to be finished by 2018.

By avoiding the need to require overtime and weekend pay, Morales said the authority believes it can shave as much as $150 million off the cost of the project.

The federal stimulus funds provided by the Obama administration must be spent by Sept. 30, 2017. Morales said that does not, however, represent a deadline for completion of the work. Any work after that date will be paid for with money from Proposition 1A, a $9 billion bond measure approved by California voters in 2008.

The Federal Railroad Administration, the state's partner in the project and the agency that provided the federal grants, has agreed to the schedule changes, Morales said.