Lalani, who had been with BT for 26 years, is leaving to pursue "personal business interests" according to Ian Livingstone, company chief executive of BT.

His replacement, Jeff Kelly a former senior manager at EDS in the US, will begin working alongside Lalani immediately.

BT Global Services, the IT services division of the telecoms giant, has with a number of under performing contracts and causing its parent company to take a which contributed to a £2.1billion loss in £8.8 billion sales last year.

Problems with the unit's £1.57 billion and i are still to be fully resolved.

In addition, in February 2009, BT lost a multi-million pound outsourcing deal with Essex County Council, three and a half years before its scheduled completion. The telecom giant is threatening legal action, while IBM has triumphantly announced it a with the county.