Hub Tower, essentially vacant after Aviva USA moved to its new headquarters in West Des Moines, might be bought by EMC Insurance Cos.

The 20-story building had been under receivership after a group of investors allowed U.S. Bank to foreclose on a mortgage in November 2009. The foreclosure was completed in early September.

EMC said in a statement last week that it had entered into negotiations to buy the building at an undisclosed price. Hub Tower is valued for tax purposes at slightly more than $17 million.

Hub Tower was built in the 1980s by Hubbell Realty Co. It is located at Seventh and Walnut streets, across the intersection from EMC’s headquarters. It shares lobby and elevator space with the Kaleidoscope at the Hub retail center, another Hubbell project.

According to a receiver’s report, Hub Tower stood to lose $3 million in rental income with Aviva moving to West Des Moines and an affiliated company, Aviva Investors, relocating a few blocks down Walnut to the Davis Brown Tower.

EMC was one of the first businesses to tour the building after it was placed in receivership, according to the receiver’s report.

“We see this as an opportunity to acquire a first-class property adjacent to our headquarters, giving us the space we need for current employees and future expansion, as well as for current and potential tenants,” Robert Link, EMC vice president of administration, said in a news release. “As a local company committed to staying downtown, we preferred to own this property ourselves and expand our footprint in the center of downtown Des Moines.” When EMC first looked at the building, company representatives said it needed an additional 25,000 to 30,000 square feet of office space, according to the receiver’s report. Hub Tower contains 281,771 square feet of office space.

Lack of office occupants first became a problem for Hub Tower and the Kaleidoscope when CitiMortgage Inc. moved out in 2009. Principal Financial Group Inc. also vacated office space in the Kaleidoscope.