Banks seeking to help turn around borrower companies should not merely extend life support to businesses doomed to fail, reappointed Financial Services Minister Heizo Takenaka said.

"If revitalization means postponing revitalization, we have no revitalization," Takenaka said. "We must instruct banks and keep a close watch on them to make sure of this."

Takenaka's statement is a warning to big banks to make sure heavy borrowers turn losses into gains, and to stop new loans if debtors fall short of their promises.