Credit card firm Credit Saison Co., 14.3 percent owned by Mizuho Financial Group Inc., will remain independent of the bank as its rivals join up with the country's biggest lenders.

"It's a matter of keeping management independence," Chief Executive Officer Hiroshi Rinno said in an interview Monday. Credit Saison wants to keep Mizuho below the 15 percent threshold, he said. Having 15 percent voting rights would make the company a Mizuho affiliate.

Credit card companies have struggled to make profits since 2006, when they were forced to repay customers billions of yen in overcharged interest.