SAO PAULO, Aug 5 (Reuters) - Grupo BTG Pactual SA , the largest independent investment bank in emerging markets, earned the highest profit in 3 1/2 years in the the second quarter after revenue beat expectations.

Net income at São Paulo-based BTG Pactual totaled 1.02 billion reais ($293 million) last quarter, compared with an estimate of 905 million reais in a Reuters poll of five analysts.

Return on equity, a gauge of how profitable a bank is, rose to 21 percent, well above the poll's 18.8 percent estimate. ROE, as the gauge is known, was the highest in a year.

($1 = 3.4865 Brazilian reais) (Reporting by Guillermo Parra-Bernal; Editing by Lisa Shumaker)