The Big Blue Bus of Santa Monica will purchase 11 new flexible 60-foot articulated buses that will join its fleet starting in 2011 for the Rapid 7 and Rapid 3 transit lines.

Company officials say the purchase allows the transit agency to add a new level of expanded service to the public. A provision in the contract allows for the option to purchase an additional ten buses as funding becomes available in the future.

Three of the new buses are being purchased with funds from the federal government’s economic stimulus package.

The articulated buses will first be used on the Rapid 7 bus rapid transit line, which is one of the agency’s busiest routes. The Rapid 3 line will also receive new buses after the initial deployment on Rapid 7 is complete, Big Blue Bus officials said.

The new cleaner burning compressed natural gas (CNG) buses will replace some of the older diesel buses in the fleet. The North American Bus Industries articulated buses include interior features for maximum comfort and convenience for all passengers, including seniors and those with disabilities, according to Big Blue Bus.

Each bus has 53 seats instead of the usual 40, and runs on clean CNG, which is 77 percent cleaner burning than diesel fuel.

“These new NABI articulated Rapid Blue buses will not only be quick, beautiful and comfortable, but they’re fueled by natural gas, which will reduce our carbon footprint and help keep the air cleaner,” said Stephanie Negriff, director of transit services for Big Blue Bus.

“We’re excited to add these to our busy Rapid lines because they have the latest features people want, and they’ll make riding more comfortable and less crowded, which will hopefully inspire people to take public transit more often.”

The Big Blue Bus currently operates a fleet of over 200 alternative fueled vehicles, carrying over 20 million passengers a year around a 52-square mile service area of Los Angeles County.