Specialty insurer National Interstate Corp. had higher revenue for its fourth quarter and full year compared to a year ago, but net income fell short because of what the company called unusual claims results stemming in part from Super Storm Sandy.

The Richfield-based insurance company reported results after the stock market closed Tuesday. Executives will discuss results at 10 a.m. today in a conference call with industry analysts.

National Interstate said it earned nearly $8.3 million, or 42 cents per share, on gross premiums written of $156.8 million for the quarter ending Dec. 31. Net income was down nearly 32 percent from $12.2 million, or 63 cents per share, on gross premiums written of $114.7 million a year ago.

National Interstate’s quarterly net income and revenue beat consensus estimates by industry analysts.

The insurer said it had net income of $34.3 million, or $1.75 a share, on gross premiums written of $573.5 million for all of 2012. Net income was down 3.7 percent from $35.6 million, or $1.82 a share, on gross premiums written of $526.3 million in 2011.

Jim Mackinnon can be reached at 330-996-3544 or jmackinnon@thebeaconjournal.com