STOCKHOLM (Reuters) - Norway's sovereign wealth fund said on Tuesday it has bought a 97.7% stake in an office property in Menlo Park in the San Francisco bay area for $217 million, in a joint venture with U.S. real estate investment firm DivcoWest.

Norges Bank Investment Management (NBIM), the world's largest sovereign wealth fund, said it bought the stake from a joint venture between Clarion Partners and Invesco Real Estate.

"The asset is unencumbered by debt, and no financing was involved in the transaction," it said in a statement.

It said the purchase price values the property at $222 million.

DivcoWest bought the remaining 2.3% of the property and will perform the asset management for the property on behalf of the joint venture, NBIM said.