Among the top 20 Indian BPO companies, ICICI OneSource is probably the only one with predominantly a voice portfolio. Continuing with its inorganic growth strategy, ICICI OneSource in 2003-04 acquired FirstRing with 800 employees and 10 US-based telemarketing clients including American Express. Traditionally strong in retail, financial services, telecom and media, its other large customers included Marks & Spencer, Providian and US credit card firm CompuCredit. It was one of the fastest growing companies doubling its manpower to nearly 4500 across its four centers in Bangalore and Mumbai.