Aflac Inc., the largest seller of supplemental health insurance, plans to add bets beyond U.S. corporate debt and Japan government bonds to its investment portfolio in 2014, Chief Financial Officer Kriss Cloninger said.

“Next year we expect to enhance our diversification by including other asset classes,” Cloninger said today at a conference held by Goldman Sachs Group Inc. He didn’t identify which markets the insurer may target.

Aflac, which sells most of its coverage in Japan, has been reshaping its investment strategy for that country after hiring Eric Kirsch from Goldman Sachs in 2011 to oversee a portfolio that is now valued at more than $100 billion. The insurer had pursued a plan to allocate more funds to U.S. corporate debt, and retreated from that strategy in favor of additional holdings of Japanese government debt after interest rates spiked.

“The greatest investment challenge has been to invest Aflac Japan’s significant cash flows in suitable investments,” Cloninger said. “Foremost in our mind is to invest in a way that takes our policy liabilities into consideration.” Jon Sullivan, a spokesman for Columbus, Georgia-based Aflac, declined to comment on Cloninger’s remarks.

Rising interest rates in the U.S. and Japan pressured a measure of solvency monitored by Japanese regulators, leading to the strategy shift, Aflac said in July. The insurer had been investing about two-thirds of its Japanese cash flow in U.S. corporate bonds hedged to yen.

Rate Hedges

Aflac is also using interest rate hedges to help cushion the effects of fluctuations in bond yields on the Japan portfolio, Cloninger said in September. Aflac has reduced holdings of risky bonds, after the company was burned by privately negotiated investments in European banks that issued debt in yen.

Kirsch has been building a team with hires from firms such as BlackRock Inc. and Deutsche Bank AG to make investments beyond U.S. and Japanese bonds. Those assets may include emerging-market debt, bank loans, high-yield bonds, mortgage- backed securities, hedge funds and private equity, he said in an interview late last year.

In October, Chief Executive Officer Dan Amos lamented that Kirsch’s hires have been stuck buying Japanese government debt, which are among the lowest-yielding bonds.

“Is the staffing-up for us to buy 80, 90 percent of our business in JGBs? The answer is, ‘no,’” Amos said on a conference call with analysts. “Don’t take this as, ‘We like it.’ We would much rather be much more diversified.”