It may be another two years before exploration company Petroceltic International can confirm that it has hit the jackpot with an extensive gas field recently discovered in Algeria, but this has not stopped its shares rising by 546%.

Chief executive Brian O'Cathain said it is too early to determine how significant the find is but that it could be very large.

"It will be 2011 before we have a good idea of how significant it is. We will then make a plan for the development of the field subject to the approval of the Algerian government. It will probably be 2013 or 2014 before it is producing gas," he said.

Shares in the company jumped last week following the announcement that the company had successfully drilled for gas at the Ain Tsila ridge, with early indicators suggesting a find much larger than expected. Petroceltic shares have been the best performers on the Irish stock market in the past 12 months, rising by more than 546% in the year to date. Davy raised its target price by 3p to 27p per share on the news.