Bus riders on the County Connection, Wheels, Tri-Delta Transit and WestCAT systems will be able to start paying transit fares with Clipper cards by the end of 2015.

A Metropolitan Transportation Commission committee on Friday authorized a contract to be negotiated for the extended Clipper service to be provided by Cubic Transportation Systems Inc.

Clipper is an all-in-one transit card in which riders can load cash value, passes and tickets. Clipper now is used to pay fares on eight Bay Area transit systems, including BART, AC Transit and San Francisco MUNI.

Under the contract, Cubic will be paid $8.3 million to bring Clipper card service to the four East Bay bus systems and five bus systems in Sonoma County.

Contact Denis Cuff at 925-943-8267 or dcuff@bayareanewsgroup.com. Follow him at Twitter.com/deniscuff