Sempra Energy plans to move its downtown San Diego headquarters to a new 16-story building in East Village in 2015, relocating approximately 700 employees from the West Ash Street location that has been its home since 1968.

The utilities company confirmed that it has signed a 25-year lease to fully occupy a 300,000-square-foot building being developed by locally based Cisterra Development, in downtown’s ballpark district. Financial terms, including expected development costs, were not disclosed by the two companies, which had been discussing the project for much of the past year.

“We felt it was important to maintain a presence in downtown, as one of the few Fortune 500 companies in San Diego and the only one with headquarters downtown,” said Sempra Energy spokesman Doug Kline.

The move will not impact workers currently located at Sempra’s SDG&E subsidiary in Kearny Mesa, Kline said.

The new Sempra headquarters building is planned for a site bounded by Island, Seventh and Eighth Avenues, and J Street. Cisterra was also the original developer of Diamond View Tower in East Village.

Jason Wood, project principal with Cisterra Development, said the developer is looking to break ground on the Sempra building this fall, with completion expected by summer 2015.

— Lou Hirsh