Insurer Metropolitan Life is selling nearly $2 billion worth of its nationwide real estate holdings, including Midtown Manhattan’s 551 Fifth Avenue and two major Chicago office buildings. Of the 15 properties offered, all except one are office buildings.

MetLife’s property holdings have a book value of $5.5 billion. The market value is likely double that amount, the New York-based company reports.

"This action does not represent any fundamental change in business strategy. We view this as an opportunistic play to reap the benefits of current market conditions," says Brian Fox, MetLife’s national marketing director. He adds the company may use proceeds from the building sales and reinvest the money in real estate holdings.

The insurer fully owns most of the buildings going to market, but some of the properties are held through joint ventures. One offering is the leased-fee position on a Los Angeles office building.

New York-based real estate services firm Cushman & Wakefield won the hotly contested MetLife listing, which the real estate services firm calls "the largest single sales assignment ever awarded any company." Los Angeles-based CB Richard Ellis also reportedly made a last-minute effort to win the assignment.

Fox credits a brisk building sales market as prompting the move to market the properties. In addition to capitalizing on a hot sales market, MetLife also will provide loans to buyers. The properties range in size from a 406,000 sq. ft. office tower in Boston to the 1.72 million sq. ft. Wells Fargo Tower in Downtown Houston.

The sole Manhattan property — 551 Fifth Ave., also called the Fred F. French Building — is valued at $400 per sq. ft., or $170 million. Only 4% of the building’s commercial space is vacant.

The two Chicago office buildings are located inside the Loop. One, a 40-story building at One South Wacker, is valued at roughly $150 per sq. ft., or $180 million. The other Chicago office building is Chase Plaza, located at 10 South LaSalle, with an estimated value of $200 per sq. ft, or $147 million.

On the residential side, two 300-unit apartment complexes, San Diego’s Carmel Mountain and Mountain Ranch, are also being sold.

Over the past two years, MetLife has sold more than $500 million worth of office buildings, including a 1.4 million sq. ft. office tower in Los Angeles.