PARIS: Immigrants who helped drive the rich world's economic growth during the boom years now face exclusion as the global economic crisis pummels economies and drives unemployment to the highest levels in 50 years, a Paris-based economic organization said Tuesday.

"Migration is not a tap that can be turned on and off at will," OECD Secretary General Angel Gurria wrote in the report. "In tackling the jobs crisis, governments need to make sure that immigrants do not fall prey to increasing xenophobia and that discriminatory practices do not worsen an already difficult situation for them."

The OECD is a forum for its 30 member countries, including the United States, Britain and France, to address economic, social and environmental policies related to globalization.

In its report, the OECD noted that in the decade before the crisis, immigrants accounted for a large share of increases in employment, reaching 58 percent in the United States and 71 percent in Britain.

But with the OECD members' economies now in the deepest downturn since the Great Depression, unemployment is soaring and could hit 10 percent by the end of next year.

This hurts immigrants disproportionately because they are over-represented in the very sectors of the economy -- construction, manufacturing and retail -- that have been hardest hit by the crisis, the OECD said.

The organization advised governments to maintain or strengthen their immigrant integration programs and reinforce their efforts against discrimination.

Governments should also take a long view and remember that "as economic recovery takes place, international migration can be expected to increase again," Gurria said.