Economic growth in Japan, Germany and Britain picked up strongly in the first quarter of the year, leading output in advanced countries which slowed down overall, the latest OECD data showed on Tuesday. But the US economy, the biggest in the world, flagged and France also turned in a lagging performance. Over a full year, Britain led top economies, growing by 3.1 percent, far outpacing the OECD average. Growth in the 34 advanced democracies covered by the OECD edged back to 0.4 percent in the quarter from 0.5 percent in the last quarter of last year. The latest OECD-area quarterly data is in line with recent signals that the recovery from the financial and eurozone debt crisis is sluggish and fragile, although some countries are pulling firmly ahead. In the 18-member eurozone, growth was low but steady at 0.2 percent, although in the broader 28-member European Union growth slowed to 0.3 percent from 0.4 percent. The Organisation for Economic Cooperation and Development, a policy forum for its members, said that its latest quarterly data "masks a wide spectrum of growth rates across countries." But on a quarterly basis, growth of gross domestic product accelerated "strongly" in Japan to 1.5 percent from 1.0 percent in the previous quarter. In Germany the growth rate doubled to 0.8 percent. "The United Kingdom also showed a strong growth of 0.8 percent, following a growth rate of 0.7 percent in the fourth quarter." In the United States and France, the rate of growth was almost flat. In the previous quarter the US economy had grown by 0.7 percent and the French economy by 0.2 percent. The Italian economy went into reverse in the first quarter, shrinking by 0.1 percent after growing by 0.1 percent in the previous quarter. However, on a 12-month comparison, the OECD-area economy grew by 2.1 percent, and this showed a slight improvement from 2.0 percent in the last quarter of last year. Among the top seven economies, Britain led the way with 12-month growth of 3.1 percent, followed by Japan with 2.7 percent, and with Italy being the only country to show contraction, of 0.5 percent.