Aviva plc reported today that it had an operating profit of 2.3 billion pounds in 2008, up 4 percent from 2007. However, the London-based insurer had an after-tax loss of 885 million pounds, which includes an unrealized loss of 153 million pounds related to investments.

“In a tumultuous year, our underlying business has shown great resilience,” CEO Andrew Moss said in a release. “Operating profits are up, and we have maintained our dividend. Bottom-line earnings have been affected by investment markets, which have predictably created significant unrealized losses during the year.”

Last year, Aviva took steps to strengthen its balance sheet, including spending 326 million pounds on restructuring moves that are expected to save the company 500 million pounds by 2010.

Life insurance and pension sales were up 11 percent, while investment sales were down 43 percent. General insurance premium income rose 5 percent, with two thirds of Aviva’s business now coming from outside the United Kingdom.

Its U.S. operations, based in Des Moines, achieved a second year of record sales growth. North American life and pension sales were up 57 percent.