The shares surged 27p to 439p, a two day gain of 34p. They are now at their highest since September; earlier this year the price was down to 350.5p.
Trading was heavy ,with Seaq putting volume at just over 14.5 million.
Significantly this performance has occurred while the market has been bereft of much in the way of ideas and action.
Yet C&W has shrugged aside the soporific atmosphere that has been a feature of the market in the past two days.
Its strength has stemmed from stories that BT has received Whitehall clearance to bid and the lingering suspicion that a break-up marauder lurks. But some of the buying was prompted by the theory that Citic, the investment group controlled from China, was growing restless over Hongkong Telecom, where Cable has a 57.5 per cent interest.
Citic has 12.9 per cent of Hongkong Telecom and stories from the colony covered most possibilities - from increasing to reducing its shareholding. There was even talk of it bidding for Cable's stake.
If BT should produce a bid the market expects around 550p a share, although there are suggestions that its main institutional shareholders may be reluctant supporters.
Most other shares had a mundane time, with the FT-SE 100 index, once again drawing comfort from New York, gaining 3.4 points to 3,348.0. Trading was again subdued, with the failure of any of the rumoured bids to appear prompting some restraint.
Government stocks provided some encouragement, chasing US Treasuries. Gains of up to pounds 13/8 were scored.
The two other main bid candidates - Kleinwort Benson and Zeneca - have yet to let down their supporters.
Kleinwort held its 701p peak and Zeneca improved 8p to 1,048p, with a large institution creating surprise by switching from Glaxo Wellcome.
Union, the financial group, (formerly Union Discount) rose 3p to 97p as rumours of corporate action resurfaced. The company made a pounds 3.7m loss last year but Smith New Court believes profits could be around pounds 900,000 this year. Assets are thought to be 170p a share. Kwik Save, the discount chain, was also pulled back into the bid arena. Speculative buying lifted the shares 18p to 623p, highest this year. Dairy Farm, the Hong Kong group, has a near 30 per cent interest and would be the favourite to strike.
Mercury Asset Management fell 10p to 825p. The fund manager could move into the FT-SE 100 index once SG Warburg, off 6p at 757p, is absorbed by Swiss Bank Corporation.
Inchcape, the international trader, reversed 8.5p to 307p. The group has extensive Far Eastern car distribution interests and cautious comments at a meeting of Jardine International Motor Holdings in Hong Kong underlined the weakness of car sales in Hong Kong and China.
A seminar by Merrill Lynch was said to be behind a 3p gain to 405p by British Airways
Building shares had a tough time. Monday's profit warning by the house builder Bellwinch underlined the industry's difficulties. British Land's disappointing performance also eroded sentiment.
Barratt Developments, Berkeley and Wilson Connolly were among those lowered. British Land fell 16p to 395p.
Hillsdown, the food group, dropped 4p to 184p on rumours a big line of stock hovered.
Cray Electronics, which issued a shock profit warning in April, sending its shares crashing from 155p, lost a further 2.5p to 54p in brisk trading. Results are due next month and about pounds 4m is expected. At one time expectations nudged pounds 35m and the company was seen as a potential bidder for Racal Electronics, up 2p at 256p following a buy recommendation from Henderson Crosthwaite.
Its analyst Brian Newman believes the shares have a "corporate valuation" of 330p and expects profits this year of pounds 75m and pounds 95m next.
Vodafone, up 5p to 230p, continued to attract US support. American shareholders account for about 40 per cent of the mobile telephone group. ED&F Man, the commodities group, continued to reflect Credit Lyonnais Laing support, gaining 9p to 170p. But Standard Chartered dipped 4p to 339p with ABN Amro Hoare Govett said to have offered "take profits" advice.
The departure of its finance director, Nick Harrington, took another 8p to 69p from Asprey, the jewellers, but Lloyds Chemists gained 6p to 224p following the departure of its chief executive, Peter Lloyds.
Merrydown, the struggling cider group, had another sobering session - off 6p at 68p.