To swing the deal, Wells Fargo Bank, also based in San Francisco, gave the South Koreans a $200 million loan at an interest rate of 4.5 percent.
Wells Fargo occupies the entire tower on a long-term lease that runs to 2026. The bank also owns its headquarters building at 420 Montgomery Street.
Goodwin Gaw, a Hong Kong-based developer, helped broker the deal and will manage the tower.
The capitalization rate for the transaction is about 7 percent, Gaw told Bloomberg. (The cap rate, a measure of real estate returns, is derived by dividing net operating income from the property by its purchase price.)
333 Market Street is expected to provide "stable cash flow," a spokesman for the South Korean funds said in a prepared statement.
South Korean pension funds also agreed to buy Berlin's Sony Center from a Morgan Stanley real-estate fund in April for about $768 million. The pension funds also purchased two buildings in Tokyo and Yokohama this month for $116 million.
The last single San Francisco office building to change hands for a comparable price was 650 California St., which sold for $300 million or about $457 per square foot in July 2007, according to Jones Lang LaSalle Inc.
"A Market Street high-rise combined with a long-term lease with Wells Fargo makes this an extremely attractive asset," Daniel Cressman, executive vice president at Grubb & Ellis Co. in San Francisco, told Bloomberg. . "It shows you how well-located, well- leased assets hold value even in difficult times."
U.S. commercial real estate values were down 42 percent in March from the October 2007 peak, according to the Moody's/REAL Commercial Property Price Index. Retail and office properties in the biggest metropolitan areas led the decline.
Prime office rents in San Francisco fell to $30.48 a square foot in the first quarter from $38.80 a year earlier, according to Colliers International, a Seattle-based brokerage. The vacancy rate for Class A space rose to 14.5 percent from 12.8 percent.
Tenants including Del Monte Foods Co., Brown & Toland Medical Group and Credit Suisse Group AG took advantage of low rates in the fourth quarter and leased about 1 million square feet of office space, according Tove Nilsen, research director for Colliers International in San Francisco.
Gaw's Los Angeles-based Downtown Properties LLC owns the Roosevelt Hotel and Bradbury Building in Los Angeles and has operated offices, hotels and golf courses in Los Angeles, New York, San Francisco and Hawaii, according to its website.
He bought San Francisco's 550 Montgomery St., a Class B office building built in 1908, for $12.65 million, or $134 a square foot, in February, according to Colliers.