Law firm Haynes and Boone LLP is expanding its Orange County office in a move to Costa Mesa from Irvine.

The firm has signed a lease for 23,000 square feet at Plaza Tower and will take the entire seventh floor, a 35% increase in space from its current location.

The move is slated for October.

OC office head Greg Michelson said the additional space will support the firm’s plans to add attorneys in various practice areas.

“Right now we have a strong focus on intellectual property, technology transactions, litigation and corporate services, but demand is also increasing for real estate, securities, insurance coverage, and class action labor and employment expertise,” Michelson said.

Dallas-based Haynes and Boone has 26 attorneys in Orange County, part of its firmwide network of 12 locations and more than 500 attorneys.

Haynes and Boone was represented in the lease by Randall Parker and Steven Card of Travers Realty Corp.

Cushman & Wakefield’s Rick Kaplan, Robert Lambert and Matt Moore represented the landlord in the transaction.