Swiss bank Credit Suisse Group has reported first quarter profits of 1.3 billion Swiss francs ($1.37 billion), a sharp rebound from the same period a year ago.

Switzerland's second-biggest bank credited "positive momentum" from a transformed business model for its jump in net profits attributable to shareholders during the first three months, up from 44 million francs in the first quarter of 2012 when it took big charges on debts and paid out higher bonuses.

The Zurich-based bank said Wednesday that results for the January-March period showed "high returns, strong client franchises, reduced cost base and lower risk-weighted assets."

Like its competitor, UBS AG, Switzerland's biggest bank, Credit Suisse has been reducing exposure to potentially-risky investment banking at a time when Europe's economy is challenged by a debt crisis.