Traders said the transition to the euro was smooth but tentative. Trading was light with low volumes of shares traded.

All shares on eurozone bourses are now quoted solely in euro values, the old national currencies having disappeared with the close of trade for 1998 last week.

At 0910 GMT, Germany's floor-traded Dax was up 133 points, 2.7%, at 5,135. Trade on the leading Continental bourse began at 0830 local time (0730 GMT) as normal, without any technical problems.

In the opening minutes of trade, Paris's Cac 40 index jumped 67 points to be at 4010 by 0905 GMT. In Milan, the MIB30 blue-chip index was up 2% while Zurich's SMI was up 136 points at 4,296.

Traders cautious

One trader said: "The open came off very smoothly. The market is still a little nervous and that is reflected in the low volume of trades."

Another said: "Investors will remain in a cautious wait-and-see position for the next one or two days, they want to see what the market is doing."

Expected gains in the value of the euro against the US dollar in initial currency trade did not materialise and so didn't hurt Germany's export-sensitive share market.

The euro was down slightly at $1.1855 in morning trade after strong overnight gains in Asia, still well up on the $1.1667 opening level set on New Year's Eve by the European Commission.

London link-up

This session also marks the start of links between the London and Frankfurt stock exchanges with traders in each centres now able to buy and sell stocks on the electronic trading platforms of the other.