SAO PAULO, July 29 (Reuters) - Banco Santander Brasil SA  
   SANB11.SA
   , the nation's largest foreign lender, is in the final stages of negotiations to create a joint venture with consumer lender Banco Bonsucesso SA, a source with knowledge of the situation said on Tuesday.     A joint venture should help Santander Brasil, the local unit of Spain's Banco Santander SA  
   SAN.MC
   , to expand in payroll-deductible lending, said the source, who requested anonymity because the matter is private. Santander and Bonsucesso did not immediately comment.      The Pentagna Guimar?es family, which founded Bonsucesso in 1992, has also helped the lender expand in lending for small- and mid-sized companies.     Veja magazine's Radar column reported the deal early on Tuesday.     The structure of the Santander Brasil-Bonsucesso venture is similar to one signed in 2012 between Ita? Unibanco Holding SA  
   ITUB4.SA
    and payroll lender Banco BMG SA, according to the source. BMG was founded three decades ago by relatives of the Pentagna Guimar?es family.     The Ita?-BMG deal called for a new company to get 1 billion reais in capital, with Itau contributing 70 percent and BMG supplying the rest. Ita? also agreed to provide unlimited funding to the joint venture and 300 million reais a month directly to BMG over five years to fund origination.    Shares of Santander Brasil rose 0.9 percent in midmorning trading in S?o Paulo.   (Reporting by Alu?sio Alves and Guillermo Parra-Bernal; Editing by Lisa Von Ahn)  ((guillermo.parra@thomsonreuters.com)(+55-11-5644-7714)(+55-119 -8346-7153)(Reuters Messaging: guillermo.parra.thomsonreuters.com@reuters.net))  Keywords: BONSUCESSO BRAZIL/SANTANDER BRASIL