Northwest Airlines' former Eagan headquarters is officially on the market.

Delta Air Lines has hired a commercial real estate broker to sell the 108-acre site near Minneapolis-St. Paul International Airport and the intersection of Interstates 494 and 35E.

The Minnesota office of Cushman & Wakefield will market the 266,899-square-foot building that once housed about 1,000 employees of Northwest, which merged with Delta last year. Delta is relocating workers from the former headquarters to other offices in Minneapolis.

The Eagan facility was built in 1985 for Northwest and has a current taxable value of $13.7 million, according to Dakota County property records.

About 36 acres along I-494 are considered excess and will be marketed separately from the building.

Cushman & Wakefield said it will market the building for lease as well as for sale. Terry Kingston, executive director of the brokerage firm, said there already has been some interest in the property but didn't specify whether that came from potential buyers or tenants.

The building is going on the block in sluggish times for the office market. The dollar total for Twin Cities area office building sales fell 80 percent, to just $247 million, for the 12 months ended June 30, according to LoopNet, a San Francisco-based real estate research firm.

A report issued this week by the Twin Cities office of Colliers Turley Martin Tucker said the area's office vacancy rate was nearly 20 percent as of the third quarter -- a four-year high.

Susan Feyder • 612-673-1723