CHATTANOOGA, Tenn. – After three years of calling both Chattanooga and Portland, Maine, home, UnumProvident Corp. has decided that Chattanooga is its public home.

“When you [list] two cities there’s calls going everywhere,” said Tom White, the company’s vice president for investor relations.

The Fortune 500 company, one of the nation’s largest disability insurers, was created by the 1999 merger of Chattanooga-based Provident Cos. and Portland-based Unum Corp.

White said the company’s operations are not changing. UnumProvident just plans to use Chattanooga in future marketing and public relations, instead of referring to both cities.

“We don’t make a big deal out of it internally, but more of the traditional home office functions are centralized here,” White said. “We really didn’t designate Chattanooga as a single home office city.”

Also, more of the company’s top executives, including J. Harold Chandler, the president, chairman and chief executive, live in Chattanooga.

The company has some 4,000 employees in Portland, about 1,000 more than Chattanooga. The heads of underwriting and human resources for UnumProvident live in Maine, White said.

Godfrey Wood, head of the Greater Portland Chamber of Commerce, said the change does not decrease the company’s presence in Maine.

“We don’t think there has been a shift of power, but a shift of operations and management efficiency,” Wood said.

UnumProvident has started building a $12 million parking garage near its Chattanooga offices and the company plans a $45 million office building.