Liberbank, a Spanish lender that took state aid, jumped in its trading debut in Madrid after exchanging subordinated debt for stock.
The shares rose as much as 58 percent to 63 euro cents, compared with its reference price of 40 cents. The stock closed at 52 cents, a 30 percent gain, valuing the bank at about 734 million euros ($946 million).
Liberbank, formed from a merger of three former savings banks including Cajastur and Caja Cantabria, took 124 million euros in state aid after Spain sought 41 billion euros in European bailout funds for its banking system last year. The listing of 30 percent of the Madrid-based lender is the first since Banca Civica SA and Bankia SA in 2011.
Under the terms of a recapitalization plan approved by Europe, Liberbank exchanged 830 million euros of junior debt for convertible bonds and shares issued at 1.11 euros apiece. The bank is offering investors who hold onto their shares for two years annual interest of 6 percent on their holdings based on the book value of 1.11 euros a piece.
Liberbank has about 47 billion euros of assets and 1,158 branches.