Hines Real Estate Investment Trust Inc. of Houston agreed last week to buy the expansive Howard Hughes Center in Marina del Rey for $506 million.

Hines disclosed the deal in a filing with the Securities and Exchange Commission last week, outlining its intent to purchase the 1.32 million-square-foot office campus from Blackstone Group. It has paid Blackstone a $30 million non-refundable deposit for the property, and the full transaction is expected to close on or before Jan. 15.

The Howard Hughes Center, which consists of five Class A office buildings and an athletic club, was constructed between 1987 and 2002. The campus was about 88 percent leased to 93 tenants at the time of the agreement.

Blackstone, one of the largest office landlords in the nation by square footage, acquired the complex in 2006. The New York real estate firm, in a joint acquisition with Brookfield Office Properties Inc., bought a 42-property portfolio from Trizec Properties Inc. for $7.2 billion.

Earlier this year, Blackstone sold seven other properties in acquired from Trizec – three in Pasadena and four in San Diego – to Prudential Financial Inc. for about $400 million.