Coincheck Inc., the cryptocurrency exchange hit by a massive theft earlier this year, has accepted a takeover bid by online brokerage Monex Group Inc., sources said Thursday.

The acquisition will be officially announced Friday. Monex Group is planning to appoint Toshihiko Katsuya, its chief operating officer, as president of the bourse, according to the sources.

In late January, hackers stole some ¥58 billion ($542 million) worth of the cryptocurrency NEM from Coincheck, the largest such heist ever. Coincheck has been criticized for not having proper security measures in place to prevent the breach.

The acquisition of Coincheck, which has a large customer base, would give Monex a foothold in the cryptocurrency industry.