Digicel, the Caribbean mobile company owned by Denis O'Brien, says it has over four million subscribers - twice as many as last year- and has invested $1.5 billion in the region.

The company now employs 3,000 and now has operations in 22 markets, covering a population of 23 million.

After launching in Haiti last year it said its customer base has reached one million there. In 2006 Digicel also launched services in Trinidad & Tobago, Turks & Caicos and Bonaire.

Last year, the company extended its mobile operations to Guyana, Martinique, Guadeloupe and French Guiana.

In October, Digicel also entered the El Salvador mobile market,  the company's first move into Central America.