It is believed that the bid beat off four other competitors, including two UK telecom companies who joined Cable & Wireless-owned Sure and Airtel Vodafone in the battle for the business.
The process took the best part of a year and the contract is believed to be one of the largest of its kind.
A specialist Lloyds TSB procurement team in the UK set the objectives and was on the hunt for a single supplier in Jersey, Guernsey and the Isle of Man for mobile and Blackberry services.
