India's largest software services firm Tata Consultancy Services (TCS) on Wednesday said the tenure of its Chief Executive Officer and MD N Chandrasekaran has been extended by five years to October 2019.Chandrasekaran, who was appointed CEO and MD for five years on October 6, 2009, has been re-appointed for another five years, TCS said in a statement.His re-appointment will be effective October 6, 2014, it added. TCS has been posting stellar quarterly growth and industry-topping performance, even though its nearest rival, Infosys had expressed concerns about clients' technology spends.