The Italian banks Unicredit and Capitalia will become operative starting Oct. 1, according to Italian News Agency ANSA.
The papers creating the merger, which will see Capitalia incorporated into Unicredit, were signed before a notary in the offices of the Milan stock exchange, ANSA said.
Capitalia shares will be withdrawn from the market on Oct. 1 and be exchanged for 1.12 Unicredit shares created through a 1.458-billion-euro rights issue.
Shareholders at Italy's number one and number three banks approved the merger at the end of July.
The 22-billion merger creates Europe's second-biggest bank and the largest in the euro zone with a market capitalization of some 100 billion euros.
The new bank will be called UniCredit Group with UniCredit Chairman Dieter Rampl holding onto his post as well as Unicredit CEO Alessandro Profumo, while Capitalia Chairman Cesare Geronzi has taken the chair at the merchant bank Mediobanca.
The estimated cost of the operation is estimated at 1.1 billioneuros, while more than 1.2 billion euros are expected from savingsby 2010.
The new bank is expected to return a net profit of 10 billion euros before 2010 and a new three-year business plan will be readyby the start of next year.
In order to abide by the conditions set by anti-trust authorities, Unicredit-Capitalia will have to sell 155-180 branches.
The new bank will have a total of 9,200 branches, 5,000 of them abroad, and some 45 million clients worldwide. Staff will number 170,00 but between 6,000 to 8,000 will be offered incentives to leave.