ECB president Jean-Claude Trichet is keeping a close watch on inflation

The decision came amid signs that unemployment could be moderating, while business and investor confidence also appeared to be positive.

With inflation worries persisting in the 12-nation eurozone, economists are betting on a rise in May - with another likely to follow shortly afterwards.

But the bank's president, Jean-Claude Trichet, said these expectations did not "correspond to ECB thinking".

Still, futures trading suggests that rates could be as high as 3.25% by the end of the year.

Until December 2005, the ECB had left its rate unchanged at 2% for more than two years.

Since then, it has made two quarter-point adjustments as Europe's major economies have picked up steam.

Inflationary pressures

The eurozone's economic outlook for 2006 is mixed, but some of its largest economies, including France and Germany, are expected to gain momentum, with reports indicating that business and consumer confidence is running high.

In its last forecast the ECB predicted economic growth of 1.9% across the 12-member eurozone bloc in 2006, compared with 1.4% last year.

The ECB is tasked with keeping prices under control, and has sees its key role as ensuring that economic growth does not come at the expense of rising inflation.

Recently, the main inflationary pressure has come from sky-high energy prices.