Online social casino developer Zynga will sell its San Francisco headquarters building for around $600 million in one of the city’s biggest property sales.

Zynga agreed to sell the Showplace Square building at 650 Townsend St. to real estate investor Beacon Capital Partners. The company will remain headquartered in the building and is leasing back 185,000 square feet, or about a quarter of the 670,000-square-foot property,

The deal values the building at nearly triple what Zynga paid $228 million in 2012. It is the largest single-building San Francisco deal since Salesforce’s $637 million purchase of 50 Fremont St. in 2015, according to property data firm Real Capital Analytics. The sale is expected to close before the end of July.

Zynga CEO Frank Gibeau said the sale will enable the company to benefit from a hot real estate market and reinvest money in its core business.