Core profits surged for the top four life insurance companies in the April-September period as the weaker yen boosted interest returns from foreign bonds, according to results released this week.

Core profit — the total of premium revenue and returns on invested premiums, minus insurance payouts and operating expenses such as wages — soared 80.6 percent from a year earlier to ¥213.2 billion at Sumitomo Life Insurance Co. and 26.6 percent to ¥220.1 billion at Meiji Yasuda Life Insurance Co.

Nippon Life Insurance Co., the nation's biggest life insurer, saw its core profit rise 7.0 percent to ¥293.0 billion, while that of Dai-ichi Life Insurance Co., the only listed company among the big four life insurers, climbed 28.1 percent to ¥179.9 billion.