Disability insurance provider Aflac Inc. said Wednesday that stronger revenue helped more than triple its third-quarter profit and beat Wall Street expectations.

For the three months ended Sept. 30, the company earned $363 million, or 77 cents per share, compared with $100 million, or 21 cents per share, a year ago. Excluding one-time investment losses of $226 million, or 48 cents per share, the company earned $589 million, or $1.25 per share, in the latest period.

In the third quarter of last year, the company booked realized investment losses of $389 million, or 81 cents per share.

Quarterly revenue rose 23 percent to $4.52 billion.

On average, analysts polled by Thomson Reuters expected earnings of $1.20 per share on slightly higher revenue of $4.68 billion.

Aflac's U.S. premium income increased 3 percent to $1.1 billion. However, total new annualized premium sales in the United States continued to reflect weak economic conditions, with sales declining 7.2 percent to $342 million. For the nine months, total new sales were $1 billion, or 6.4 percent lower than a year ago.

The company said its new premium sales in the U.S. will fall short of its objective of flat to 5 percent growth this year. In Japan, where the company does a significant portion of its business, the company expects its annual objective of flat sales to a 5 percent increase.

It forecast fourth-quarter operating earnings in the range of $1.08 to $1.16 per share, and full-year adjusted profit of $4.75 to $4.83 per share. On average, analysts are projecting earnings per share of $1.15 and $4.77 for the respective periods.

The company also declared a fourth-quarter dividend of 28 cents per share.

Shares of Aflac slipped 68 cents to $39.61 in after-hours trading, after falling $1.73, or 4 percent, to close the regular session at $40.58.