The 134-year-old Chicago Stock Exchange now handles about 0.5 percent of US stock trading.[file photo]

CHICAGO - The Chicago Stock Exchange announced on its website Friday that it has entered into a definitive agreement to be acquired by an investor group led by Chongqing Casin Enterprise Group (Casin Group).

The Board of Directors of Chicago Stock Exchange has unanimously approved the transaction, the announcement said. But, it still needs to get regulatory approvals, and the final acquisition is expected to close in the second half of 2016.

The terms of the transaction have not been disclosed.

Chicago Stock Exchange CEO and President John Kerin said the acquisition is the best outcome for the clients, shareholders and the trading community as a whole "after an in-depth review of strategic alternatives for the exchange".

It is learned that the Chinese company will preserve current business operations and proprietary trading platforms of Chicago Stock Exchange, and the management team will remain in place upon the closure of the transaction.

Casin Group, headquartered in Chongqing, is a leading diversified holding company in China that has investments in financial services, real estate and environmental services.

It would be the first US stock exchange being purchased by a Chinese company. The 134-year-old stock exchange now handles about 0.5 percent of US stock trading.