Spain's CaixaBank is to lay off nearly 8,300 staff as part of a mega merger with its smaller rival Bankia to form the country's largest domestic lender, a union said Tuesday. "They are proposing cutting 8,291 staff members," the Workers' Commission (CCOO) wrote on Twitter following talks with the management, saying the bank was also to shut down 1,534 branches. emi/hmw/mg/tgb