The Phoenix Cos. overstated its fourth quarter and 2008 earnings by $46 million as the result of an error in accounting on its income taxes, the insurer said.

The company revised its original earnings, reported Feb. 27, saying in a new filing it had a net loss of $378.3 million for the fourth quarter of last year. Adjusted operating income was $29.2 million.

For 2008, the company reported a net loss of $726 million and adjusted operating income of $76 million.

“Our headline loss reflects a brutal economy in which all businesses have had to operate in uncharted territory,” said Dona D. Young, chairman, president and chief executive officer, in a prepared statement. “The volatile markets affected many aspects of our business.”

The estimated impact of the fourth quarter markets and investment income declines was $11.4 million.

The company’s debt-to-capital remains low at about 22%, Young said, noting that during 2008, it paid down or repurchased about $170 million in outstanding debt and have no maturities until 2032.