Their attention fuelled a 14.5p gain to 233p, the best performance by any blue chip. Takeover stories went the rounds; so did suggestions that the break-up value is nearer 300p a share.
What was clearly apparent was that the market was short of Gas shares and relatively modest demand created an exaggerated advance.
Still Gas has been under close scrutiny since Shell felt obliged to deny long-running rumours it intended to bid. British Petroleum, off 9p at 658.5p, is the latest predatory candidate.
In February, just over 10 years after privatisation, Gas's institutional shareholders and army of 1.5 million Sids will vote on the plan to split the group into two - Centrica and BG plc. It looks as though some institutions feel they are underweight ahead of the demerger and are quietly trying to strengthen their position in an unwilling market.
Many believe the bid - if it does appear - will not materialise until after the break-up, which will leave one side supplying 20 million domestic customers and running the Morecambe Bay gas field and the other operating the pipeline network and the rest of the gas exploration and production business.
The gas giant also, at last, seems to be getting in control of its hugely expensive take-or-pay North Sea gas deals. The first settlement was with BP, costing pounds 293m. Other agreements are expected in the next few months.
Shell put on 5p to 978p ahead of analysts' meetings today in London and in New York on Monday.
The rest of the market struggled. Early gains were cut back and Footsie had to be content with an 8.2-point advance to 3,990.7 after at one time enjoying a 27.4 climb.
Orange, the mobile phone group, dialled the right number, gaining 9.5p to 178,5p on the likelihood of improved revenue as it renegotiates its arrangements with BT. Cable and Wireless, another beneficiary through Mercury, put on 4p to 452p.
Glaxo Wellcome managed a 6p gain to 944p despite sell advice from HSBC James Capel. The stockbroker has, it seems, cut its profit expectations because of sterling's strength and a modest slip in margins. Capel is said to have reduced from pounds 3.1bn to pounds 2.93bn for this year and from pounds 3.25bn to pounds 3.08bn for next. ML Laboratories was little changed at 202.5p after switching from the dying USM to full listing.
Hays and Mercury Asset Management "celebrated" their promotion to the Footsie index with falls. With NatWest Securities deciding the time is ripe to remove Hays from its buy list after more than three years, the shares of the business support group fell 3.5p to 534.5p. The investment house now regards Hays as no more than a hold. Fund manager MAM lost 4p to 1,231.5p. Biocompatibles International, elevated to the 250 index, jumped 37.5p to 742.5p.
Associated British Foods, a narrow market, improved 18.5p to 459p, a peak. A flurry of stories went the rounds including suggestions the family controlled giant was thinking of paying a special dividend. Recently its Australian offshoot announced a special payment and the feeling is the parent will follow its example.
Transport Development Group advanced 10p to 178.5p. Merrill Lynch undertook a 9.8 per cent (14.5 million shares) buyback at 180p.
Stakis, the casino and hotel group, rose 2p to 91p; the 22.2 million rump of its rights issue was placed at 85.5p.
Kier, the builder, made a firm debut, hitting 184.5p from its 170p placing.
British Mohair, the textile group, fell 18.5p to 100p on its profits warning and Baggeridge Brick crumbled 14p to 97.5p on its 46.5 per cent profit setback.
Wiggins, the property group, rose 0.5p to 8p. It placed 14.5 million shares with Compania Financiera La Granja, a company associated with Maurice Smulders, a property developer. La Granja now has 4.26 per cent.
CPL Aromas gained 16.5p to 186.5p on suggestions a hovering line of stock had been cleared. The shares were 507p in the spring.
Ideal Hardware fell 10p to 642.5p after four directors sold 8.44 per cent (1.79 million) at 630p
Great Western Resources, an oil and gas group, added 2p to 21.5p as Forcenergy, a US group, bid equal to 23p cash a share.
Gabriel Trust, an AIM-listed financial group, has acquired 14.85 per cent of Ofex-traded Chartfield Fund Management, which embraces the Waverley unit trusts. It is thought Gabriel, headed by David Pearl, will attempt to gain control of Chartfield, run by Mark Flawn Thomas, who has 32 per cent. In the summer Chartfield agreed to buy stockbroker John Siddall and fund manager Fairisle. But the deal failed to go through. Chartfield shares are 60p; they opened on Ofex at 90p in April. Gabriel fell 1p to 15p.
John Ritblat, head of British Land, is increasing his holding in Artesian Estates by selling properties at Luton and Norwood in exchange for shares, lifting his stake to 26.47 per cent. The shares held at 68.5p; the Ritblat deal was fixed at 70p.