Japan's second-largest private life insurer, Dai-ichi Life Insurance Co. Ltd., has agreed to buy U.S. insurer Protective Life Corp. for $5.7 billion in what would be the largest acquisition by a Japanese insurer, Reuters reported. Dai-ichi Life said it will issue up to 250 billion yen ($2.4 billion) in new shares to help finance the purchase of Protective Life, which is the 36th largest U.S. insurer by premium income. The Japanese insurer will retain existing management at the Birmingham, Ala.-based company, which recorded net income of $393 million in 2013. Faced with weak growth prospects at home amid Japan's aging population, Dai-ichi Life and other Japanese insurers have been buying assets in more dynamic markets from the United States to Southeast Asia.