Thayer Lodging Group has agreed to buy the 336-room Ritz-Carlton San Francisco from Host Hotels & Resorts for about $161 million, according to Bloomberg Businessweek. Thayer Group says it plans to invest up to $17 million in renovations on the property within the next two years. The sale took place amid a rapid rise in average daily rates in the San Francisco market, with nightly room rates up 7.5% this year through April.