The OECD said it expects growth to accelerate in the US and the euro zone in the first and second quarters of this year after the slowdown seen in the fourth quarter. Growth is expected to remain solid in Japan and the UK, it said. OECD chief economist Jean-Philippe Cotis said activity is estimated to have reaccelerated on both sides of the Atlantic after an unexpected weakening at the end of last year. But he said there are still risks to the economic outlook. The OECD said it expects US GDP growth to be around 1.1 pct in the first quarter and 0.9 pct in the second, after slowing to a rate of just 0.4 pct in the fourth quarter of last year due to adverse one-off effects of the late summer hurricanes. "Recent US data point to a sharp rebound in the first quarter of this year, even after taking into account that unseasonally mild weather in January boosted retail sales and some of the other high-frequency indicators. Job creation has remained robust," he said. The Federal Reserve's interest rate rises have now essentially removed any remaining monetary accommodation but there may be some scope for "limited" further tightening, it said. "With limited if any economic slack left and some pressures on costs there may be a case for limited further tightening, subject to the incoming data, including the evolution of house prices," said Cotis. Euro zone growth is projected to accelerate to 0.6 pct in both the first and second quarters from 0.3 pct in the fourth quarter. Cotis said "hard" indicators continue to paint a distinctly weaker picture for the euro zone than the "softer" but more forward-looking survey information. "The strong external side should feed through to euro area domestic demand and a rebound can be expected in the first half of 2006. Even so, by mid-year, the euro area-wide output would still be significantly below potential," he said. The OECD said the European Central Bank should only raise rates again once the economic situation clearly requires it. "Further out, removal of monetary accommodation should be based on unambiguous signs that slack is shrinking and that underlying inflation pressures are mounting," said Cotis. Within the euro zone, the OECD said it expects the German economy to grow 0.6 pct in the first quarter and 0.4 pct in the second after recording zero growth in the fourth quarter.