A major casualty was Yorkshire-Tyne Tees TV Holdings, where takeover expectations had been inflamed by MAI's purchase last week of Pearson's near 14 per cent interest.
With Granada sitting on 14 per cent, the scene seemed set for a rip- roaring bid battle.
But Mr Dorrell has, in effect, destroyed any such prospect, although with two large, dismayed shareholders likely to try to sell their stakes Yorkshire still looks vulnerable to a strike.
With Granada and MAI ruled out of the action, Yorkshire shares tumbled 36p to 486p; MAI, which paid a fancy price for its Yorkshire interest, fell 8.5p to 260p and Granada 5p to 585p.
Scottish TV, with near 20 per cent shareholder Mirror Group Newspapers seemingly restrained from bidding, lost 26p to 454p. MGN fell 4p to 136p.
Carlton Communications gave up 11p to 959p although unease was cushioned by the prospect of a splendid set of interim figures today.
Other TV shares lower included HTV, off 6p to 196p, and Ulster 22p to 811p. Among radio shares, Capital put on 16p at 442p and Radiotrust, seen as a simple way to gain exposure in a tightly held sector, rose 8p to 77p.
The rest of the stock market held on to New York's coat tails. Another powerful transatlantic display ended a downward drift and by the close the FT-SE 100 index was showing a 7.3 points gain at 3,291.8.
Michael Heseltine's green light for a bid battle at shipbuilder VSEL lifted the shares 88p to a 1,783p peak. In early trading they had slumped 63p.
GEC, which had looked to be out of the running, slipped 2p to 315.5p with British Aerospace off 10p at 537p.
The suspicion continues to lurk that BAe could be tempted to overpay for VSEL, leaving itself vulnerable to a strike from GEC. Vosper Thorneycroft, seen as the next shipbuilding target, rose 19p to 823p.
Retail shares were unsettled by Marks & Spencer's disappointing advance. With the sector still grieving over WH Smith's profit warning, high street shares encountered determined selling.
M&S fell 10.5p to 408.5p, dragging down the likes of Boots (14p to 516p) and Kingfisher (6p to 460p). Smith lost a further 6p to 336p.
Static results from TJ Hughes, the department store chain, left the shares 6p down at 74p. But Next continued to shrug off the gloom. Still drawing strength from the recent upbeat trading statement, the shares improved a further 2.5p to 329.5p.
P&O slipped 9p to 594p. The shares were ruffled by news that Celebrity Cruise Lines, a US group, had suffered a $2.55m first quarter loss against a $3.45m profit because of faltering demand.
Thorn EMI added 10p to 1,220p as the market took chairman Sir Colin Southgate's comments on its music division as offering some encouragement to potential bidder Walt Disney.
Northern Foods and Unigate gave ground as Societe Generale Strauss Trunbull said sell, and Redland retreated 12p to 450p with Robert Fleming offering sell advice.
Carnaud Metalbox jumped 325p to 2,725p as Crown Cork and Seal, a US group, launched a takeover bid.
Grand Metropolitan, showing analysts its Italian operations, was little changed at 384.5p; BBA, with a German visit lined up, shaded 2p to 213p. Morgan Crucible, also courting analysts, firmed to 351p.
Water shares got a lift from UBS, with Thames 7p higher at 495p.
Financials remained on bid alert with Lloyds Abbey Life 6p firmer at 409p. Standard Chartered put on 4p to 242.5p on NatWest Securities support.
BAT Industries rose 4p to 493p as Barclays de Zoete Wedd said buy.
Builders remained depressed as commentators seemed to be vying with each other to paint the bleakest outlook. Barratt Developments lost 7p to 182p.
Bass, buying a Madrid bingo club, rose 5p to 561p. Interim figures are due today; Williams de Broe is looking for pounds 255m against pounds 242m.
Proudfoot, the management consultant, fell 12p to 48p following a profit warning.
Queens Moat Houses had another busy session with nearly 39 million shares printed; the price dipped 1.5p to 16.75p. Regal Hotels returned from suspension a shade lower at 34p and Prime People, the recruitment group, was relisted at 6p.
Newcomer Langdon Foods traded at 3.5p against a 3p placing price.
Upton & Southern had a busy session with Seaq putting volume at 13.5 million. The price edged ahead 0.25 to 2p. Shares of the struggling retailer have risen 0.75p in two trading sessions.
Harmony Property was another minnow attracting attention. Turnover was put at nearly 12.4 million shares with at least one stockbroker seemingly prepared to mop up stock coming on offer. The price shaded 0.75p to 3.5p.
o Dealings are due to start next week on the 4.2 market in the shares of European Property Holdings, which has been created to buy commercial property in the former Soviet Union. Its first acquisition, however, is a Belgian property, pumped in by managing director Julian Nyman. Through Williams de Broe it has offered shares at 30p, raising more than pounds 2m.
oTamaris, the revitalised nursing homes group, is set to buy three homes in Scotland. The deals, which should double the group's bed population to more than 800, will be financed by a placing and open offer. Other acquisitions are expected. Headed by William Fitch, Tamaris acquired four Ulster properties in January. It increased interim profits from pounds 2,000 to pounds 118,000. The shares rose 0.25p to 2.25p.