Google Inc. bought six office buildings northwest of its Silicon Valley headquarters from Starwood Capital Group LLC and Blackstone Group LP in a $585 million deal, two people with knowledge of the matter said.

The properties are part of the Pacific Shores Center office park in Redwood City, Calif., about 11 miles from Google’s main office in Mountain View, said the people, who asked not to be named because the transaction is private. The company said in its quarterly report filed Thursday that it bought land and buildings for $585 million, without details.