Hub Tower has sold for slightly more than half of its assessed value of $13.2 million, according to a property record filed Wednesday.

Employers Mutual Insurance Co. (EMC) paid $7 million for the 20-story structure that helped trigger downtown redevelopment when it was built in the 1980s by Hubbell Realty Co. and other prominent Greater Des Moines companies.

EMC has said it plans to move some operations to the structure at 699 Walnut St., which was placed under receivership in November 2009 after U.S. Bank foreclosed on a $16 million loan that had been assumed by an investment group led by Greater Des Moines commercial real estate broker Kurt Mumm.

Soon after Mumm acquired the property, it began losing tenants, with CitiMortgage Inc. and Aviva USA moving out of the building.

Hub Tower was built as a mix of office and retail space. The 20-story skyscraper was part of the downtown renaissance of the 1980s; its developers sported prominent business names - Equitable Life Insurance Company of Iowa, Iowa Power and Light Co. and Hubbell Realty Co.

Hubbell Realty continues to own the Kaleidoscope retail space, but it no longer has an ownership interest in Hub Tower.

EMC has asked the city of Des Moines for a $293,000 economic development package to move its EMC National Life Co. from Urbandale to the Hub Tower. The company employs approximately 81 people with an average annual wage and benefits package in excess of $100,000, according to a city report.

Two floors will be renovated to accommodate the move.