The United States’ economy is crying out for policy stimulus far more loudly than Europe’s, a global economic outlook report said today.

While inflation is at “uncomfortable” levels in both Europe and the U.S., an Organisation for Economic Co-operation and Development (OECD) report said there is a strong case for government or central bank action in the U.S., but its near-term outlook for Euro region does not point to such a need.

The report comes in the same week the U.S. Federal Reserve slashed interest rates by three-quarters of a percentage point, to 2.25%. This brings the central banks cuts to a full 2% so far this year and to 3% since last August. Economists are widely expecting further cuts at the Fed’s next meeting on April 30.

Meanwhile, the European Central Bank has shunned heavy rate slashing for fear of rising inflation. “The ECB’s Trichet [EBC president] has been very steadfast maintaining his focus on inflationary risk,” said Samarjit Shankar, director of global strategy at The Bank of New York Mellon, at a recent presentation. The ECB remains “stubbornly hawkish” on the downside risks to growth, Shankar noted.

“The euro zone is in a very interesting situation,” he said. “We could see lower growth.”

Against this backdrop, the OECD notes that the weak housing market, shrinking household incomes and tight lending standards in the U.S. have led to weaker global growth prospects, adding that these three problems are unlikely to fade soon. “The US economy is now essentially moving sideways, if not contracting outright,” the OECD assessment reads. “It may be premature to declare a recession, but with the pace of activity so far below potential, economic slack is widening rapidly.”

Across the pond, however, the deceleration has been less abrupt although growth is still set to remain on the low side of potential for some time, the report said.

On the inflation front, the report’s author Jorgen Elmeskov, acting head of the OECD’s economics department, said the latest data out of the U.S. suggests higher prices might be leaking into product areas outside of energy and food, those traditionally most volatile.

US headline CPI inflation stood at 4 % last month, and the latest core PCE reading was at 2.2%. Meanwhile, notwithstanding euro appreciation, headline HICP inflation in Euro-denominated regions reached 3.3% in February 2008 and core inflation continues to inch up, approaching 2.5%.

Today’s OECD report noted that pressures are now reaching beyond the origins of the U.S. subprime mortgages. Amid continued turbulence in financial markets a more general wariness has developed prompting a re-pricing of risks, it said.

Central banks must balance the risks associated with commodity prices, continued market turbulence and short-term trade offs between inflation and output when making policy decisions, the OECD said. “The case for policy stimulus is stronger in the U.S. than in Europe and both US monetary and fiscal policymakers have already acted forcefully,” the report concluded. “In the euro area, by contrast, the near-term outlook for activity and inflation does not point to a need for stimulus and automatic fiscal stabilisers will provide more support than in other regions.”

Also today, the U.S. Conference Board released its February composite index of leading economic indicators. The private research group said the index fell 0.3%, to 135.0 in February after a series of declines since October. The Board said the leading index has fallen 1.5% since last August, a 3% annual rate.

The U.S. Federal Reserve’s next meeting is scheduled for April 30, while the European Central Bank will make its next monetary policy announcement on April 10.

Economists are widely expecting further cuts from the U.S. central bank. “The key issue is to first unclog the credit markets and get the wheels turning again,” said Charmaine Buskas, senior economics strategist at TD Securities, in a note. “The economy will naturally have to reach a bottom, and with sufficient stimulus, the Fed can engineer a modestly softer landing than otherwise. As such, we expect considerable further easing in the near term.”