An important stake in Firstsource, one of India's leading business-process outsourcing companies, has been put up for sale in a move that could trigger an ownership shake-up in the sector.

Metavante, a US-based banking technology group, has appointed Goldman Sachs to find a buyer for its 20 per cent holding in the Mumbai-listed company, India's third-biggest BPO by revenues. First-round bids are expected this month.