The San Diego Metropolitan Transit System, the municipal agency that operates the city’s mass transit buses and trolleys, said it selected Clear Channel Outdoor as the new operator and media provider for MTS’ 400 bus shelters, 322 of which currently offer advertising.

Terms of the contract weren’t revealed.

Clear Channel Outdoor said MTS expects to build 100 bus shelters over the next five years as it expands the system.

Based in New York, Clear Channel Outdoor Holdings Inc. (NYSE: COO) has about 750,000 displays in 40 countries including 48 of the largest 50 markets in the United States.