Southern California Gas Co. is planning to move from its longtime headquarters after signing the largest office lease of the year in downtown Los Angeles.

SoCalGas will leave its namesake Gas Company Tower at 555 W. 5th St., where it has been a primary tenant since the building was completed in 1991, and move a block north to another skyscraper, at 350 S. Grand Ave.

The utility signed a long-term lease for nearly 200,000 square feet on eight floors in the Grand Avenue building on Bunker Hill often known as Two California Plaza, its new landlord said, and is expected to move by spring 2026 after building out the new offices. The gas company will also have an office on the ground floor to serve customers.

The Bunker Hill neighborhood has been a bright spot for office leasing in what has been an extended period of declining occupancy in downtown's financial district since the pandemic ushered in a movement toward allowing employees to work from home.

Bunker Hill has benefited from having a mixture of building types, including offices, apartments and hotels, as well as being one of the city's main cultural destinations with such institutions as Walt Disney Concert Hall, the Broad Museum and Colburn School of music.

"We are somewhat of an island in downtown," said landlord Shaul Kuba, whose company CIM Group owns Two California Plaza. "There is so much culture, with a daytime and nighttime population."

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The building is part of an office, hotel and retail complex that dates to the 1980s, a period when Bunker Hill, a former residential neighborhood, was being remade from the ground up in a process of "urban renewal" meant to transform blighted neighborhoods.

With the arrival of SoCalGas, Two California Plaza will be home to two major Los Angeles institutions. City National Bank is already headquartered there and currently has its name affixed to the top. As part of the lease agreement with SoCalGas, its name will replace City National, Kuba said.

The new offices will be about two-thirds the size of SoCalGas's current space in the Gas Company Tower. A spokeswoman for the utility, Erica Berardi, did not address why the company is moving but said its current lease expires at the end of 2026.

"SoCalGas is excited to maintain our headquarters in downtown Los Angeles, where we have a long history as one of the area’s largest tenants," she said.

The lease is the largest in downtown Los Angeles this year, according to analysis from Raise Commercial Real Estate.