By Nivedita Bhattacharjee MUMBAI (Reuters) – An exodus of senior executives and staff at Indias second largest IT outsourcing firm, Infosys Ltd, could hamper efforts to win lucrative contracts in the United States and Europe, and weigh on its profit growth outlook for this year. Nearly a fifth of the workforce had left the company in the quarter ended December following the return from retirement of founder N.R. Narayana Murthy in June to turn around the company after a string of disappointing results. So far, nine senior executives have left. Infosys has the highest attrition rate among Indias top-three IT outsourcing firms.