Bentley stepped down from British Gas in February to pursue his ambition to become a chief executive, after it became clear he was not in the running to take the top job at parent company Centrica.
Bentley, who has no telecoms experience, will take over from current boss Tony Rice on 1 January as the firm shifts its base to Miami, Florida.
“Phil will take forward the company’s strategy of establishing CWC as the leading provider of mobile, fixed line and broadband communications services in Latin America and the Caribbean region,” CWC said in a statement yesterday.
Rice, who has led the company since 2008 and steered its split from Cable & Wireless Plc in 2010, will stay on until the end of January to help with the handover.
Bentley’s new job could mean a pay cut: he earned £860,000 in salary and pension payments at Centrica in 2012, and with a £635,000 cash bonus and long-term incentives had a total package worth more than £3m.
CWC said yesterday that he will receive an annual salary of £800,000 and have an annual bonus opportunity of 1.5 times that salary.
Before working for Centrica, Bentley worked for Diageo and spent 15 years with oil group BP.
At British Gas he oversaw a 30 per cent rise in sales to £14bn and an increase in profits from £300m to £1.1bn.