Beach buy.

The 113,000-square-foot office building at 520 Broadway in downtown Santa Monica will change hands at the end of the month in a transaction that marks the continuation of a buying spree by Westside real estate investor Kevin Green--and a selling spree by investor William Chang.

Green's Palisades Associates LLC is paying $31.6 million, or about $280 a foot, for the building, and will spend an undermined amount upgrading the property. The building is about 80 percent occupied. Tenants include Liberty Media Corp. subsidiary Ascent Media.

"We're eager to reposition the building in the marketplace to attract a long-term quality tenant," said Green. "We're strong believers in the downtown Santa Monica market."

Last fall, Green's IRP Beverly Hills Associates LLC bought 9440 Santa Monica Blvd. from Douglas Emmett for $21.9 million.

The sale is the third in seven months for Chang, who sold 811 Wilshire and Pacific Center--both in downtown Los Angeles--for a combined $62.5 million.

Coldwell Banker Commercial Westmac's Timothy Macker and Chris Holland are representing Green while Charles Dunn Co.'s Charles Desantis is representing the seller.

Staff reporter Danny King can be reached at [phone] ext. 230, or at [e-mail].