Fairfax County is seeking state funds to help pay for its share of Silver Line costs — a move that has at least one other funding partner upset.

The county agreed in 2011 to pay for one Metrorail station and two garages as part of an agreement to help cut costs for the second phase of the $6 billion Silver Line, which will extend the railway from Reston into Loudoun County, past Washington Dulles International Airport.