Market report: Friday close

SHARES of controversial oil exploration company

Since the company floated in February, the shares have traded on just 12 days. Stock market bears who sold short were again feeling the squeeze today as the shares climbed another 6½p to 147½p after touching 160p, where the company is valued at £240m, on turnover of less than 750,000.

The shares were frozen by the London Stock Exchange last Friday as it was no longer possible to conduct an orderly market in them. That was because the number that had been sold short exceeded the number in issue, making it impossible for the bears to close their outstanding positions.

That, in turn, drove the price steadily higher. Founding shareholders have now been asked to free up liquidity by selling up to 35% of their holdings.

Bear raider Simon Cawkwell, who trades under the alias Evil Knievil, has sold short 300,000 shares at prices ranging from 15p to 115p. He has been heavily criticised by directors of White Nile, who have complained to the Financial Services Authority and asked for an investigation.

Evil Knievil has also demanded an inquiry into the activities of White Nile. He wrote yesterday: 'There is more chance of the Queen taking elocution lessons from John Prescott than of White Nile delivering capital gains for current purchasers at this level.'

Within six days of the original flotation, the shares had soared to 138½p, at which point a halt was called to trading. They returned from suspension last week after the company concluded a deal with the Sudanese government in the south of the country to look for oil in the war-torn province.

White Nile will carry all the exploration costs while netting only 60% of the profits. To make matters more confused, French oil giant Total says it owns the sites earmarked by White Nile.

Share prices traded in a narrow range for much of the session but lost ground after Wall Street kicked in this afternoon with falls. The FTSE 100 index fell 5.6 to 4999.4.

Tesco added 1¼p to 315p. The supermarkets chain tightened its grip on the food retail market during the four weeks to 22 May, according to the latest survey by Taylor Nelson Sofres. It now accounts for 30% of the market.

Asda, part of Wal-Mart, continued to lose market share to the likes of J Sainsbury, down ½p at 285¼p, while Wm Morrison, ½p better on 190¾p, showed signs of imminent improvement. US broker Goldman Sachs says Tesco's extensive price cutting in May shows that trading conditions are getting tougher.

Logistics outfit Exel added 7p to 859p. US broker Morgan Stanley has lifted its target price from 780p to 900p. It says there is value in the shares but warns they are not cheap and admits there are concerns on growth.

Insurance underwriter Advent Capital began trading on Aim following a placing by broker Numis Securities at 35p, valuing the business at £35m. The shares opened at 36½p before settling at 37½p.

Bob Morton's Vislink rose 2p to 31p after being awarded a £994,000 contract to supply wireless camera systems in the US. On Aim, shares of investment group Tower returned from suspension 2p down at 3.75p.