British Gas was the catalyst for the energy display. The shares jumped 19.5p to 228.5p, the highest since June, as the long-running rumour of a takeover bid from the Shell oil giant was dusted down and given sudden prominence.
The market has grown increasingly convinced that Shell, as well as British Petroleum, are casting around for major acquisitions. Besides British Gas, the two generators, National Power and PowerGen, have in recent weeks been put forward as likely victims of the ambitions of the oil giants.
BP gained 5p to 675p and Shell 10.5p to 996.5p. National Power rose 8.5p to 453.5p and PowerGen 8p to 573p. ScottishPower joined in, adding 7p to 329p.
Most oils were firm. Lasmo put on 5p to 213.5p as Panmure Gordon drew attention to the group's attractions and predicted the shares would top 300p by the end of next year.
Lasmo has the distinction of beating off a takeover assault from Enterprise Oil. It is still looked upon as a bid candidate, with a US strike thought likely to emerge.
Hopes the remaining electricity distributors will soon be engulfed in corporate action lifted London Electricity 10.5p to 636.5p and Yorkshire Electricity 11p to 746.5p.
British Energy, figures on Thursday, was squeezed 2.5p higher to a 126p peak.
Elsewhere activity was inhibited not only by the Budget but by growing uncertainty over interest rates and the problems the strength of sterling is creating for some companies.
Government stocks scored gains on the back of the PSBR figures.
Footsie could muster only a 3.9-points gain to 3,962.1 with second and third-line stocks mostly in retreat.
Cookson, the industrial materials group, fell 10p to 226.5p as the rumoured bid - Friday's hot tip - failed to materialise.
BT fell 6.5p to 364.5p, overshadowed by first-time dealings in Deutsche Telekom.
Profit warnings undermined sentiment. Forward, a maker of printed circuit boards, crashed 149.5p to 132p; Meltek, a computer support group, slumped 25p to 72.5p; and Colleagues, a recruitment group, suffered a 17p fall to 52.5p despite the promise of a maintained final dividend. Although the accompanying trading statement was subdued, it was a cross of 770,000 shares at 50p which created the hesitancy. Publisher Rushmere Wynne shaded 0.25p to 2p following a warning of a 10-month pounds 100,000 loss.
Vanguard Medica jumped 55p to 565p as the SmithKline Beecham giant confirmed plans to market its migraine drug. Toad, the vehicle securities group, advanced 7.5p to 87.5p; it has won two contracts which could push the fledgling group close to break-even.
WS Atkins, an engineering consultant, reached its highest since its July flotation. It has achieved the contract to be project manager of the first phase of an electronic components plant in South Wales. Sold at 215p, the shares gained 26p to 348.5p.
Jefferson Smurfit, the packaging and paper group, added 2.5p to 166.5p as Salomon Brothers said buy. The shares are down 27 per cent from their peak, hit two years ago, and Salomon says the company has an "impressive track record of buying undervalued and earnings-enhancing assets; it has never built a new paper machine".
House of Fraser continued to attract bid speculation, up 5.5p to 157p. Hambros, the merchant bank which has seen off vulture fund Regent Pacific, gained 12p to 247.5p as favourable comment from Barclays de Zoete Wedd mingled with thoughts that the group is still vulnerable to a strike.
Provend, the vending machine group, made a lively debut, briefly trailing its placing price but ending with a 7.5p gain at 132.5p.
Ockham's decision to float its stockbroking arm, Wise Speke, left the insurance group 2.5p down at 82.5p.
Bluebird, the toy maker, was enlivened by the $755m US toys merger between Mattel and Tyco Toys. The prospect of more toy deals in the run-up to Christmas was enough to lift Bluebird 13.5p to 180p. The shares, however, have had a dismal run, falling from 357p earlier this year.
Fibernet, rolling out a national network linking computers with faxes, telephones and videos, edged forward 2p to 124.5p after reporting a pounds 328,000 profit. Stockbroker Greig Middleton expects a loss of pounds 1.9m this year with a surge into profits of pounds 10.4m in the following year.
rEmerald Energy stuck at 2.5p. It has, through an institutional placing by stockbroker WH Ireland, raised pounds 7.5m and stands to get a further pounds 4.3m from a placing and open offer.
The cash is needed to develop oil projects in Columbia. Dr Keith Hewitt, leading the Colombian charge, has enjoyed remarkable success in the areas Emerald is exploring. It is said the projects each have the potential of 1 billion barrels of oil.
rEyecare Products, a spectacles maker, has formed a company with Lantis, a US group, which involves the marketing of the high profile Donna Karan range.
Lantis is paying 37.5p for a 15 per cent stake in Eyecare and has an option to buy another 12.3 per cent at between 47.5p and 57.5p. Eyecare rose 3.5p to 33p.