In what Prudential Financial is calling a “mutually beneficial partnership,” the Newark, N.J.-based firm has announced that a Japanese company is investing $500 million in its operations.

Nippon Life Insurance Co, one of the world’s largest life insurers, announced it would purchase a $500 million, 10-year exchangeable surplus note issued by Prudential Sept. 16. The transaction is expected to close Friday (Sept. 18), subject to customary conditions, the firms said.

Under the terms of the deal, Nippon Life can exchange the surplus notes for shares of Prudential Financial common stock at any time, beginning on the fifth anniversary of issuance of the note.

This is Nippon Life’s second investment in Prudential, already holding 2.56 million shares of the company, according to published reports.

John Strangfeld

John Strangfeld, chairman and CEO for Prudential Financial, said the company is “pleased” Nippon Life selected it as an investment.

“We view this investment as a mutually beneficial partnership,” Strangfeld said in a statement. “Our two companies will continue to seek opportunities to work together and to promote the well-being of the life insurance industry around the world.”

Ikuo Uno, Nippon Life’s chairman, said the investment “is a reflection of the longstanding relationship, based on mutual respect and admiration, between our two companies.”

Uno said Prudential shares Nippon Life’s “values and belief in providing the highest quality products and services to customers in Japan, the United States and around the world.”

Nippon Life provides products including whole life, medical, nursing coverage and annuities for more than 10 million individuals as well as group insurance products for more than 230,000 corporate clients in Japan.