Dhaka, April 15 -- Half of the world's 75 poorest countries are experiencing a widening income gap with the wealthiest economies for the first time this century in a historical reversal of development, the World Bank said in a report on Monday.

The differential between per capita income growth in the poorest countries and the richest has widened over the past five years, according to the report.

"For the first time, we see there is no convergence. They're getting poorer," Ayhan Kose, deputy chief economist for the World Bank and one of the report's authors, told Reuters.

"We see a very serious structural regression, a reversal in the world ... that's why we are ringing the alarm bells here," he said.

The report said the 75 countries e...