Baker & McKenzie and Debevoise & Plimpton are advising on Japan’s Meiji Yasuda Life Insurance Co’s purchase of U.S.-based StanCorp Financial Group Inc for $5 billion, the latest in a series of multi-billion deals featuring Japanese insurers.

Meiji Yasuda, Japan’s third-largest life insurer by premium revenue, said it will pay $115 per share for StanCorp, and will fund the purchase with cash on hand.

Portland, Oregon-based StanCorp, which offers insurance and retirement products to companies and individuals, has about $2 billion in premium revenues and posted a 2014 net profit of $210 million, Meiji Yasuda said.

Baker & McKenzie is advising Meiji Yasuda on the deal, led by Tokyo partner Jiro Toyokawa and Chicago partner Craig Roeder. They are being assisted by partners Kiyoshi Endo and Toshio Ibaraki in Tokyo, Jakub Teply and Maura Ann McBreen in Chicago, and Thomas May in New York. Debevoise & Plimpton is representing StanCorp.

With weak growth prospects at home due to a rapidly ageing population, Japanese insurers have been actively pursuing overseas acquisition opportunities for future growth.

In June, Tokio Marine Holdings Inc agreed to buy U.S. insurer HCC Insurance Holdings Inc for $7.5 billion, in what is the biggest M&A deal so far this year by a Japanese company.

In February, Dai-ichi Life Insurance Co completed a $5.6 billion acquisition of Protective Life, a mid-sized U.S. life insurance firm, in a deal that featured Baker & McKenzie and Debevoise & Plimpton.