(Bloomberg) — Aflac Inc., the largest seller of supplemental health insurance, climbed the most since 2012 after fourth-quarter profit beat analysts' estimates on sales gains in the United States and Japan.

Aflac rallied 3.4 percent to $61.09 at 9:42 a.m. in New York, erasing the company's loss for the year. The gain was the largest in the 85-company Standard & Poor's 500 Financials Index.

Net income rose 4.1 percent to $703 million, the Columbus, Georgia-based company said yesterday after the close of regular trading. Operating profit, which excludes some investing results, was $1.29 a share, topping the average analyst's estimate by one cent. A deal with Japan Post helped the first increase of new annualized premium sales in the country in seven quarters.