Cushman & Wakefield has signed a 12-year lease to occupy the 24th and 25th floors of downtown’s Wilshire Grand Tower, the real estate services firm said Monday.

It plans to relocate from the Figueroa at Wilshire building across the street in October.

The company was already tied to the Wilshire Grand – the West Coast’s tallest building at 1,100 feet tall – as its leasing agent. The Business Journal reported last week that Cushman planned to take space in the skyscraper alongside owner Korean Air Lines Co. Ltd., which is slated to take one floor. The Southern California Association of Governments is said to be close to signing a lease for two floors.

If those deals are completed, 11 floors of office space would remain available below 30 floors of hotel space and four floors containing a restaurant, bar, and other public amenities. The project also includes a parking garage and retail space. CoStar lists the tower’s monthly asking rents at $4.25 a square foot.

Cushman’s space spans 34,456 square feet – smaller than its current block of 53,000 square feet, but meant to be used more efficiently and provide for growth. El Segundo-based Aref & Associates is set to design open work areas, a two-story atrium, and a café.

“Our decision to move to the Wilshire Grand Center was all about our employees,” said Andrew McDonald, Cushman’s regional managing principal for Los Angeles and Orange County, in a statement.

John C. Cushman III, chairman of global transactions, noted that Cushman has long promoted downtown’s development as a financial and business center.

“Wilshire Grand Center will soon be in the ranks of the most important and iconic buildings in America,” he said in a statement.

Real estate reporter Daina Beth Solomon can be reached at [email protected]. Follow her on Twitter @dainabethcita for the latest in L.A. real estate news.