Japanese civil engineering group Infroneer said on Tuesday it would buy Japan Wind Development from Bain Capital for about $1.4 billion ¡ª an acquisition that will expand its renewable energy business.

Japan Wind Development says it operates 293 wind turbines, the vast majority in Japan, with a combined generation capacity of 570,850 kilowatt hours. It is the country¡¯s market leader for maintenance of wind power generators, Infroneer said.

The deal is expected to close in late January.

The sale was made through a competitive bidding process, a person familiar with the matter said, declining to be identified.

Bain Capital, which led a management buyout of Japan Wind Development in 2015 for ?9.7 billion, declined to comment.

Reports of the acquisition costs sent shares in Infroneer sliding 6% on Tuesday.

Renewable assets have become increasingly attractive as Japan seeks to transition to a zero-emission economy.

Mergers and acquisitions involving Japanese companies in the renewable energy sector have climbed more than eight times to $1.8 billion for the year to date from the same period a year earlier, marking the highest level since 2019, LSEG data showed. The number of deals at 28 is a record high.

Infroneer has worked on two wind farms in northern Japan which have since been sold.