The fledgling group, which arrived on the stock market only two years ago at the equivalent of 67p, is now capitalised at around pounds 4.6bn.
Despite its heady share progress Colt has yet to make a profit. It lost pounds 32.5m last year.
The Global deal is likely to herald a wave of consolidation in the still fragmented telecom business and Colt may feel the need to merge.
Zeneca - as rumours swirled of a Continental deal - was the other star performer. In often feverish trading the drugs group surged 205p at one time, closing 100p higher at 2,520p. After the stock market closed the drugs group confirmed it was in "advanced" talks with Astra of Sweden.
Zeneca has been one of the market's favourite bid candidates since it was demerged from Imperial Chemical Industries five years ago.
Trading perked up a little from Monday's barren display and Footsie, at one time up 63.1 points, ended with a comfortable 39 gain to 5,615.7. Supporting indices edged ahead.
Blue chips drew strength from the growing conviction that the Monetary Policy Committee will feel obliged to reduce interest rates although few believe it will indulge in the full 1 percentage point cut being advocated in some quarters.
Still another gloomy retail survey appeared to underline the need for a significant, say half-a-point, easing.
British Aerospace, at one time 8p higher, continued to flutter on hopes of a Continental deal. There were suggestions it could clinch the rumoured deal with DaimlerChrysler Aerospace tomorrow. The shares ended 7p lower at 504p.
Prism Rail threatened to derail some of the other train operators after rolling out disappointing interim figures. Stagecoach, with half -year results tomorrow, shaded 11.75p to 230p. The group is expected to produce pounds 94m against pounds 73.1m; there is some vague talk it has encountered problems at its Porterbrook off-shoot. Railtrack was shunted 49p down to 1,521p by cautious comments from HSBC, which suggested the shares should be 1,350p.
British Airways was lowered 6.5p to 366.5p as it became apparent that Warburg Dillon Read had shaved its year's profits estimate by some pounds 100m to pounds 300m. Most forecasts are above pounds 400m.
Cadbury Schweppes, the confectionery and soft-drink group, fizzed ahead 30p to 913p on further consideration of its US bottling deal, and Allied Domecq, 18p to 530p, and Whitbread, 24p to 763p, responded to cheerful comments on pub trading from Scottish & Newcastle, 15.5p higher at 719.5p.
But pub tiddler Paramount collapsed 6.5p to a 10p low ahead of next week's shareholders' meeting. Five years ago the price was 105p.
The oil giants drew comfort from the modest revival of the crude price from its historic low. British Petroleum put on 23p to 883.5p and Shell, also helped by the prospect of an analysts' meeting scheduled for later this month, improved 14.5p to 349.5p. But Premier Oil, seemingly doomed to relegation from the mid cap index, lost 2.25p to 18.75p.
Pizza Express was sliced 32.5p to 812.5p by director selling. Six of its nine-strong boardroom team cashed in by selling 1.15 million shares at an average price of 837p. The deals realised a pounds 4.5m profit for the six.
Director buying gave a lift to struggling Spring Ram, the bathroom and kitchen group. The shares rose 1p to 6p after chairman Roger Regan and two other directors acquired 900,000 shares.
Arcadia, the retailing group devastated by a profits warning, fell a further 6.5p to 175p as a Warburg downgrading of its former partner, Debenhams, piled on the agony. Debenhams fell 5.5p to 330p.
The latest boardroom shenanigans at Newcastle Utd clipped the shares 3.5p to 94.5p. Blockleys, the building materials group, softened 3.5p to 41.5p. It said it was looking to unlock shareholder value. The company urged shareholders not to accept the bid from Natural Building Materials, which already has 10.5 per cent of the capital and is striving to take its support to 29.9 per cent. It expects acceptances representing a further 20 per cent.
Hewetson, another building materials group, firmed 6p to 150p - after the market closed, it reported a possible bid approach. Engineer Jones & Shipman, another to attract bid interest, gained 1.5p to 12p. Mining group Waverley hardened to 6.5p after bidder Corporate Resolve revised its offer.
Arm, the computer chip group, jumped 105p to 1,195p on expected trading links and Acorn, with an Arm stake, rose 4.5p to 79p. Allowing for tax influences it seems the Arm interest could be worth 100p for each Acorn share.
SEAQ VOLUME: 854.8m
SEAQ TRADES: 55,349
GILT INDEX: 114.34 +0.45
EMERALD ENERGY'S Colombian oil adventure is looking distinctly jaded. The shares, 10p earlier this year, fell 0.5p to 3.25p.
There is disappointment over the results so far achieved at its Gigante well and, with its shares on the slide, it is clearly encountering difficulty raising the additional cash - perhaps as much as pounds 10m - it needs to continue its Colombian exploration. Emerald's position is not helped by the collapse of the crude oil price.
DEAN CORPORATION, in its new slim-line form following the hiving off of its housebuilding and pub refurbishment operations, traded at 7p.
The demerged business, called Artisan, was around 6p on AIM. Before the splits the group's shares were 10.5p. Dean, which is due to become Environmental Property Services, hopes the break will improve its share price which hit 19.5p earlier this year. It has paid pounds 2.75m for IPM Engineering.Reuse content