LONDON, July 15 (Reuters) - The decline in the value of trade in the world's major industrialised economies began to slow in the first four months of 2009, though volumes continued to fall at double digit rates in the first quarter, the OECD said on Wednesday.
"Since July 2008, G7 total merchandise trade values continued to decline, but at a slower pace since February 2009," the Organisation for Economic Cooperation and Development said in a report.
"The ... overall trend is remarkably similar across countries, backing up the notion of a synchronised trade collapse."
The OECD said the rates of decline in the United States had shown signs of slowing since January while Japan's particularly marked decline in merchandise trade since October 2008 had slowed early in 2009 and picked up in April.
In Britain, the negative trend showed signs of levelling off in March and April though net trade remained negative.
The global downturn has hit trade hard, dampening both demand and supply, while the credit crunch has hampered financing.
World Trade Organisation chief Pascal Lamy told Reuters last month that the contraction in trade volumes this year was likely to be bigger than the record nine percent the group forecast in March.
The OECD report said G7 exports had declined 22.8 percent in the first quarter of 2009 compared to the same period in 2008, while imports were down 16.8 percent.
But seasonally adjusted declines in trade volumes were less marked when compared to the last quarter of 2008, with exports falling 13.6 percent and imports 10.5 percent across the G7.
Balance of payments data for the OECD's 30 members also showed double-digit drops, though again the figures suggest that the declines are slowing.
"Compared with the previous quarter, the value of exports and imports of goods and services in OECD countries, measured in seasonally adjusted current price U.S. dollars, continued to drop significantly, albeit less dramatically," the report said.
"The seasonally adjusted figures fell by 13.4 percent and 15.2 percent respectively."
(Editing by Stephen Nisbet)