RICHFIELD, Ohio Unusually high claims losses resulted in a drop in third-quarter earnings from operations at National Interstate Corporation during the third quarter of 2011.

The parent company of leading motorcoach industry insurer, National Interstate Insurance, said it had net after-tax earnings from operations of $5.9 million, or 31 cents a share, during the three months ended Sept. 30, compared to same-period, year-ago net after-tax profits from operations of $7.67 million, or 40 cents per share.

For the first nine months of this year, net after-tax earnings from operations were $23.76 million, or $1.22 per share, virtually unchanged from same-period 2010 earnings of $23.41 million, or $1.21 per share.

Gross premiums written by National Interstates various insurance units totaled $120.9 million during the third quarter of this year, up 3.7 percent from a year ago.

For the first nine months of 2011, gross premiums were $411.7 million, a 23.6 percent gain, reflecting the impact of the companys acquisition of Vanliner Insurance Co. in July 2010.

Both 2011 periods had higher net investment income offset by lower underwriting profits.

"Our top line has performed consistently well throughout the year with growth in existing businesses and the favorable impact of the Vanliner premium," said Dave Michelson, National Interstate president and CEO.

"2011 third-quarter earnings from operations included the adverse impact of approximately 26 cents per share related to claims costs above those experienced in the 2010 third quarter for our recreational vehicle product line and two alternative risk transfer programs," said Michelson. "Weather-related losses comprised approximately 20 percent of this unusual claims variance," he added.

National Interstate directors approved a quarterly dividend of nine cents per share, payable Dec. 12, to shareholders of record Nov. 28.