WASHINGTON (Dow Jones) - The role of offshore financial centres in sheltering illicit financial flows from the developing world grew in the last decade, according to a report released on Thursday.

Banks in the US, the UK and Europe declined slightly in importance as a destination for illicit funds from developing countries, but remained the most important endpoint for those funds.

Offshore centres' share of developing world illicit outflows rose from 21.8 percent in 2003 to 34.2 percent in 2006, according to the report from Global Financial Integrity (GFI), a group that advocates for greater transparency in the financial system.

As defined by the GFI report, those offshore centres include among others, the Bahamas, Bermuda, Cayman Islands, Guernsey, Hong Kong, Isle of Man, Jersey, Liechtenstein, and Panama.

The findings come as Western nations are pressuring offshore centers to boost transparency and cooperation with other nations on money-laundering and tax evasion.

The study is based on data from the Bank of International Settlements, which only measured total outflows from developing countries to various regions of the world. GFI then used models to estimate the amount of those funds that were tainted by tax evasion, money-laundering, or other crimes.

Offshore centres' increased importance was Offshore centres' increased importance wasfunds that were tainted by tax evasion, money-laundering, or other crimes.

Offshore centres' increased importance was driven by a larger share of illicit funds from Asia, the Middle East and North Africa, the report said.

Developed world banks were the destination for between 46 percent and 67 percent of illicit flows from developing countries.

The report measured financial flows from the developing world from 2002 to 2006. GFI previously estimated that illegitimate funds flowing out of developed countries at a rate of $1 trillion per year.