UBS Group AG agreed to buy Credit Suisse Group AG in a historic, government-brokered deal aimed at containing a crisis of confidence that threatened to spread across global financial markets.

The Swiss bank is paying more than $2 billion for its rival, according to people with knowledge of the matter. It will be an all share deal and priced at a fraction of Credit Suisse's price at the close on Friday, when the bank was valued at about 7.4 billion francs ($8 billion.)

The plan, negotiated in hastily arranged crisis talks over the weekend, seeks to address a massive rout in Credit Suisse stock and bonds over the past week following the collapse of smaller US lenders. A liquidity backstop by the Swiss central bank failed to end a market drama that threatened to send clients or counterparties fleeing, with potential ramifications for the broader industry.

US authorities have been working with their Swiss counterparts because both lenders have operations in the US and are considered systemically important in Switzerland, Bloomberg reported earlier. Authorities sought an agreement before markets opened again in Asia.