John Hancock Financial Services is selling its landmark John Hancock Tower and two other Boston headquarters buildings. The insurer, one of the nation’s largest, has suffered major investment losses this year.

The sale of these properties should yield a solid profit for the firm, which has reportedly lost a net $241 million so far this year.

Insurer Metropolitan Life put nearly $1 billion worth of commercial real estate on the market earlier this fall in order to take advantage of high investor demand for office properties.

The number of insurers paring their real estate portfolios underscores how poorly the industry has done. Some executives have even said that the insurance business is in its worst shape in a decade.

The tallest building in New England, the 62-story John Hancock Tower was designed by architect I.M Pei in 1976.