James Capel remained tight-lipped on its plans for the 210.5 million shares it had bought, refusing to add to a statement that it had "hedged the market risk of the holding through a structured transaction with Crescent Holdings GmbH, a member of the Olayan group of companies".
Athens-based Olayan was described yesterday as "usually a long-term shareholder". Its interests include Coca-Cola bottling rights and a Land Rover distribution franchise in Saudi Arabia.
The pounds 405m sale of shares in the Grid to Capel for 192.5p a share left dealers confused about the ultimate buyer of the stake. Wide-ranging rumours during the day linked the holding with, among others ,George Soros, the American speculator, and GEC, the defence and electronics group.
Some speculated that the sale might actually be no more than a ruse to allow Hanson to appear to comply with a requirement to reduce its holding in the Grid while retaining an economic interest in the shares. As the owner of a regional electricity company, Eastern Group, Hanson is under an obligation to cut its holding in the Grid to less than 1 per cent.
Hanson denied that it had any interest in the shares after the sale and described as coincidence the fact that Niven Duncan, a consultant to Olayan, was also the former chairman-designate of Eastern Group. Christopher Collins, vice chairman of Hanson, said: "Our transaction was with James Capel. This is not a case of us warehousing our shareholding. We no longer have any economic interest in the Grid, ownership rights or beneficial interest."
Shares in National Grid rose 6p to 205p on the takeover talk, despite the fact that the company's independence is, in theory, protected by a government "golden share", which caps individual stakes at 15 per cent.
Hanson became the single biggest shareholder in the National Grid with 210.5 million shares when it bought the country's largest regional electricity company, Eastern Group, last year.
The 12 Recs in England and Wales owned the Grid before it was demerged and floated last December. The regulator, Stephen Littlechild, gave them until the end of this year to sell off almost all of their stakes.
Hanson's Eastern was the last Rec to dispose of its stake. All have now complied with the regulator's order by reducing their stakes in the Grid to less than 1 per cent or handing on the shares to their own shareholders.
A spokesman for Hanson said the group would use the proceeds to reduce debt and described the sale as part of an ongoing disposal programme in the run-up to a planned four-way split into the group's main constituent businesses.
Under the Grid's articles, companies that hold an electricity licence or are wholesalers of power in Britain are barred from holding more than 1 per cent in the Grid. There is also a 15 per cent stake limit on other companies and the Government also has a protective "golden share" in the company, which prevents a predator moving in without consent.
Comment, page 21