CHATTANOOGA, Tenn. – Disability insurance firm UnumProvident Corp. reported Wednesday that third-quarter earnings rose 54 percent, primarily due to improved results at its group income protection unit.

Quarterly earnings rose to $167.6 million, or 55 cents per share, from $108.7 million, or 36 cents per share, last year.

Excluding investment gains of $41.8 million, or 14 cents per share, operating earnings for the latest quarter were $125.8 million, or 41 cents per share, matching the estimate of analysts surveyed by Thomson First Call.

Revenue for the period rose 4 percent to $2.66 billion from $2.56 billion last year.

Shares of UnumProvident closed up 22 cents, or 1.6 percent, to $14.22 on the New York Stock Exchange.

UnumProvident is based in Chattanooga, Tennessee, and employs about 3,600 people in Portland, Maine. The company was created by the 1999 merger of the Unum Corp. of Portland and The Provident Cos., based in Chattanooga.