WASHINGTON, May 20 (Reuters) - AT&T ( T ) on Wednesday filed suit against California officials seeking a court order declaring it does not have to continue offering traditional copper wire phone service to new customers as it vowed to spend $19 billion on modern telecom services.

California requires the U.S. wireless carrier to spend $1 billion annually to maintain a century-old telephone network that few use, AT&T ( T ) said, saying the network now serves just 3% of households in AT&T's ( T ) California territory.

AT&T's ( T ) suit named the California Public Utilities Commission and the state attorney general. The CPUC did not immediately respond to a request for comment.

AT&T ( T ) said it is committing to investing $19 billion in California as it works to connect more than 4 million additional households and businesses across California by 2030 and added IP-based networks are far more reliable and efficient.

AT&T ( T ) also Wednesday asked the Federal Communications Commission for permission to discontinue traditional phone service in parts of California where it has faster, more reliable service available. It also filed a petition with the FCC to declare that California's rules that effectively require AT&T ( T ) to power, repair and sell traditional phone service, even after the FCC has authorized the service to be phased out, are preempted by federal standards.

AT&T ( T ) added that transitioning from copper will save an estimated 300 million kilowatt-hours annually by 2030 or the equivalent of eliminating emissions from 17 million gallons of gasoline. The company added that California has already suffered about 2,000 outages from copper thefts this year and it struggles to find replacement parts.

The federal government and virtually all states where AT&T ( T ) historically offered copper-wire service "have now eliminated outdated regulatory obstacles" allowing AT&T ( T ) to begin powering down its old network and increasing its investments in modern communication technologies, the company said in its lawsuit filed in U.S. District Court in southern California.