Hana Financial Group Inc. said Monday it plans to buy an additional 40 percent stake in the Korea Exchange Bank (KEB) in April by swapping shares, taking firmer control of South Korea's No. 5 lender.

Hana Financial completed the deal to buy a 51.02 percent stake in KEB from Lone Star Funds for 4.69 trillion won ($4.34 billion) in February 2012, making it Korea's No. 3 banking group. It also bought further stakes to raise its holdings to 60 percent last year.

The group said it plans to buy the remainder from KEB shareholders to raise its stake to 100 percent by swapping its share with 5.28 KEB shares.

The group said the share swap will be made in early April after it gains approval during the shareholders' meeting slated for March 15.

"The move will help boost the group's share prices by dispelling uncertainty and raise the value of the group," Hana Financial Group said in a statement.

The group also added that the share swap will not compromise its post-takeover agreement with the KEB labor union made in February, under which Hana Financial will run KEB as an independent entity and maintain its current brand and wage system until at least 2017.

But the KEB union claimed that the move was in clear violation of the agreement, which stipulates that Hana Financial may begin talks with the KEB union on a possible merger process five years after the takeover. (Yonhap News)