The Massachusetts Pension Reserves Investment Management Board (Mass PRIM) is selling a San Francisco office building to Tishman Speyer.

The Bush Street building is to be sold for approximately $380m (€345m), according to sources.

The deal, at close to $700 per square foot, will be one of San Francisco’s largest office building sales this year.

Once closed, it would reflect a yield of less than 3.7%.

Mass PRIM wrote in a board meeting document that, at a sales price of $366m, the low forward return projection would have been a 3.7% cap rate and a 5.8% IRR.

The pension fund is 98.9% owner of 333 Bush, with the remaining ownership in the joint venture being held by DivcoWest Properties.

The pension fund held title to the property through its separate account manager, AEW Capital Management.

San Francisco-based Bard Consulting was hired as an adviser for a second opinion on the sale.

The sale of the property will earn the pension fund a significant profit.

Mass PRIM set the property’s value at $312-581 per square foot.

The asset is considered a core-plus/value-add investment, with strong current income from occupancy in the high 80% range.

Value could be added by leasing up empty space.

The pension fund and Tishman Speyer declined to comment.