The Group of 20 (G20) major economies need to remain vigilant against protectionism despite the fact that they have thus far managed to avoid a significant intensification of trade or investment restriction, the World Trade Organization (WTO) said on Monday.

"Unemployment rates are expected to remain high throughout 2010. Coupled with uncertainties about when, and how strongly, sustained global economic growth will resume, this points to the need for G20 governments to remain vigilant in opposing protectionism," the WTO said in a latest report.

It also called on G20 governments "to devise and announce publicly as soon as possible exit strategies from any trade restrictions or other measures with trade restrictive or distorting effects that were taken in response to economic conditions last year, so as to undercut protectionist pressures in favor of making these measures permanent."

The report, prepared jointly with the Organization for Economic Cooperation and Development (OECD) and the United Nations Conference on Trade and Development (UNCTAD), was aimed at assessing the G20 countries' trade and investment measures since last September.

It noted that some G20 members had continued to implement new trade restrictive policies, in apparent contradiction to their pledges made at their summit meetings in London and Pittsburgh last year.

However, "the overall extent of these restrictions has been limited and an escalation of protectionism has continued to be avoided," it said.

According to the report, the volume of world trade is estimated to have fallen by around 12 percent in 2009, back to a level at which it stood in 2006.

There is recent evidence of a resumption of growth in world trade and output, particularly an apparently strong recovery of trade growth in the Asia-Pacific region in the past few months that has been led by China and some other East Asian economies.

But whether trade growth in 2010 could be sustained is still a question because of factors such as macroeconomic and trade policies.

The report urged G20 nations to "work diligently and quickly" to strengthen the multilateral trading system and to improve multilateral market access by concluding the Doha Round of trade opening negotiations.

"International trade and investment offers one of the surest routes forward to non-inflationary and sustained global economic recovery," it said.