Manulife Financial has pricedS$500 million of green bonds, a series of 3 per cent, 12-year notes whose proceeds the insurer will use for sustainable investments.

The company said the bonds are the first green bond of benchmark size issued by a life insurance company. The bonds will bear a fixed coupon for the first seven years, after which the coupon will be set at 0.832 per cent over the prevailing five-year Singapore dollar swap rate.

The notes mature on Nov 21, 2029 and the offering is expected to close on Nov 21, 2017.

Manulife's first green bond is only the second Singdollar green bond and the third by Singapore corporates to hit the market.

In April, CDL Properties kick-started the development of a green bond market in Singapore, raising $100 million from the first domestic deal.

In August, DBS Bank became the first Singapore corporate to tap the international markets for its US$500 million (S$678 million) five-year green bond.

For this latest bond, from Manulife, in-principle approval has been obtained from the Singapore Exchange Securities Trading for the listing and quotation of the bond, the company said.

"As one of the world's largest life insurers, our success is linked to the long-term well-being of our customers, our employees and the communities we serve around the world," said Manulife's chief financial officer, Mr Steve Roder.

"We are also a long-term investor which puts us in a unique position to help facilitate the transition to a more sustainable economy. Issuing a green bond aligns our financing with our existing green investment activities," he added.

DBS Bank, HSBC (Singapore) and Standard Chartered Bank have been appointed as joint lead managers for the offering.