After yesterday's flurry, analysts say higher volumes should have been traded overnight on the London Exchange if a real bid was emerging, but investors for the moment are biding their time. Hardman's entry onto a stock exchange index may also have driven some institutional buying.

Some suggested Shell was making a bid in an effort to replace the liquids reserves it recently slashed from its balance sheet but the volume attributable to Hardman would in reality make negligible impact on Shell's global reserves figure.

Independent analyst Peter Strachan said insiders hold a belief that the whole Mauritanian Offshore Basin area will yield 4- 5 billion barrels of oil plus several tens of tcf of gas over the next couple of decades and that the known 400 mmbbls in Chinguetti and Tiof is just the start.

He added that some figures suggested Pelican could be estimated to hold over 6 tcf of gas and with floating LNG technology would be a valuable source of energy for Europe.

HDR reached $1.27 today on turnover of 17 million shares at press time.