Despite $400 million in claims payments and other costs related to Superstorm Sandy, fourth-quarter net income at Nationwide jumped to $176 million in 2012 from $35 million in the prior year.

CFO Mark Thresher says Nationwide saw “very solid growth” in direct-written premiums, especially in Main Street commercial, specialty commercial and agribusiness lines of business. P&C direct-written premiums grew to $4.03 billion during the last quarter of 2012, compared to $3.53 billion during the same time in 2011—the result of a combination of rate increases and an increase in exposures, such as in Main Street commercial.

“These business are continuing to do better,” Thresher says. Additionally, he called out new writings in agribusiness. “This business is doing very well,” says Thresher, who adds that retention also improved.

Adding to top-line growth is the addition of Harleysville Insurance, which was acquired on May 1, 2012. Thresher says Harleysville added $800 million in P&C premiums during 2012. Yearly direct written premiums increased more than 10 percent to $16.2 billion. However, the acquisition has yet to significantly impact net-operating income due to purchase accounting, integration and other costs.

The Columbus, Ohio-based insurer says lower weather-related claims and growth in the P&C business performance boosted yearly net income by about $1.62 billion—from a net loss of $677 million in 2011 to a net profit of $940 in 2012.

“One of the things we look at is non-weather loss ratios—things we can control, because you can’t control weather,” says Thresher. “There is an improvement,” he adds, as Nationwide continues to manage and simplify expenses, and look hard at the underwriting process.

Nationwide says it saw “one of the largest single-year increases in recent history” in yearly total operating revenue, from $20.7 billion in 2011 to $22.4 billion in 2012. Yearly net-operating income increased about 43 percent to $741 million, compared to $517 million in 2011.

However, fourth-quarter net-operating income fell to $18 million, compared to $142 million for the same period in 2011, due to Sandy, which struck the Northeast on Oct. 29. P&C operations posted a $91 million loss in operating income in the fourth quarter, compared to a net gain of $8 million during the same three months in 2011. But the segment reversed a loss in operating income for the year, turning a 2011 net-operating loss of $213 million into net operating income of $117 million in 2012.

The commercial-premium growth and lower weather-related claims—at least in comparison to 2011—improved results, says Nationwide. The company says weather claims were $1.5 billion in 2012—”more than expected,” but less than the record-setting $2.3 billion in weather claims the insurer booked in 2011.