Cable & Wireless Communications (CWC) says it has made "good progress" in its first year as a stand-alone business.
The company reported a 21% rise in pre-tax profits to $462m (£286m) for the year to the end of March.
CWC runs consumer telecoms services in 38 territories outside the UK.
Cable & Wireless demerged last year, splitting into two companies - CWC and Cable & Wireless Worldwide (CWW), which focuses on telecoms services to business, mostly in the UK.
The company said that strong contributions from Macau and Monaco had been offset by poor trading in the Caribbean.
"Financially, three of our business units, Panama, Macau and Monaco & Islands, have progressed," it said in a statement.
"The Caribbean has been more difficult than we anticipated at the time of demerger and we continue to face weak or declining economies across the region."
The firm has been reshaping its Caribbean operations in the face of reduced tourism and increased competition.
Shares in the company closed down almost 12% in London.
But CWC's shares have fared better than those of CWW since the demerger in March 2010.
Since then its stock has fallen 9%, compared with a 40% drop for CWW.
On Tuesday, CWW reported a £140m annual profit, compared with a loss of £94m the year before when it had faced large costs related to the demerger. Before exceptional items, profit rose 23% to £143m.