Storebrand ASA (STB), Norway’s second- largest publicly traded insurer, fell the most in more than four months in Oslo trading after lowering the reported solvency ratio at its life insurance unit.

Storebrand fell as much as 9.5 percent, the biggest decline since Feb. 14, and was down 7.6 percent at 20 kroner as of 11:21 a.m. in the Norwegian capital, making it the biggest decliner on the Bloomberg Europe 500 Insurance Index. (BEINSUR)

Storebrand restated the first-quarter solvency ratio for its life insurance unit to 146 percent from 163 percent after it received a letter from the Norwegian Financial Supervisory Authority, or Finanstilsynet, regarding its calculation of the measure, the Oslo-based company said in a statement. The solvency ratio is a measure of a company’s capacity to absorb losses.

“Storebrand’s view has been built on a different interpretation of the regulation than Finanstilsynet has communicated,” the company said. “Storebrand Life Insurance Group will going forward report according to Finanstilsynets method.”

Storebrand said it had an internal target of 150 percent for the measure, which is “materially” above the regulator’s 100 percent minimum requirement. The solvency ratio for the company as a whole and reported profit weren’t affected, the company said.

To contact the reporter on this story: Stephen Treloar in Oslo at streloar1@bloomberg.net

To contact the editor responsible for this story: Christian Wienberg at cwienberg@bloomberg.net