Medeva, until yesterday regarded by many as tomorrow's drug star, crashed 100p to 116p following a surprise warning that profits would be below expectations because of US problems.
Wellcome was hit by suggestions its Zovirax herpes drug would face fierce competition from a new SmithKline Beecham product, Sanciclovir, which could appear on the market a year ahead of schedule.
According to Nigel Barnes at Hoare Govett, Sanciclovir is a 'significant improvement' on Zovirax. He estimated Zovirax sales this year of pounds 740m, representing about half Wellcome's profits.
With Wellcome's anti-Aids drug, Retrovir, enduring considerable controversy, the drug group's shares have been under pressure. They fell 10p to 624p, their lowest this year.
The Medeva upset and last week's bearish comments by Smith Barney, the US investment house, left Glaxo Holdings 15.5p down at 523p, another 1993 low, and Zeneca 10p off at 613p. James Capel rates Fisons, down 3p at 165p, Glaxo and Wellcome as sells with SKB, up 1p at 416p, and Zeneca on the buy list.
But Boots' decision to drop its Manoplax heart drug was well received, with the shares putting on 13p to 435p.
Oils were again ruffled by the growing possibility that Iraqi oil will start flowing again following a deal with the United Nations over weapon site inspections. At one point the crude price plunged to below dollars 16, its lowest since the Gulf war, on the prospect of an already soft market having to accommodate another 600,000 bulk barrels.
British Petroleum fell 6.5p to 285.5p and Shell 4p to 607p.
The new BT partly paid shares reached 172p, closing at 168p. Seaq put turnover at 187 million shares. The old shares were also active, with a Seaq volume of 72 million and the price improving 5p to 413.5p. BT was responsible for about one-third of the market's turnover.
As expected the successful conclusion of the latest BT saga stirred the rest of the market out of its lethargy, but the poor drug and oil performances restricted the FT-SE 100 index to a modest 9.9-point gain at 2,842.9. The Maastricht uncertainty was again an inhibiting influence and talk of lower European interest rates made little impact.
Insurances were strong, with Legal & General's new business figures inspiring the life sector. L&G rose 13p to 510p and Prudential Corporation 6p to 348p.
Composites were excited by takeover talk, with Sun Alliance edging forward 4p to 382p (after 387p). The shares have climbed from 335p since it was disclosed in June that TransAtlantic Holdings, the French/ South African group, had nudged its shareholding above 3 per cent.
Donald Gordon, head of TransAtlantic, has described the holding as a 'strategic stake'. TransAtlantic already embraces the Sun Life insurance group.
But few observers think TransAtlantic will bid. The theory is its presence will encourage another group to move for Sun Alliance.
Other insurers were in the takeover frame. Commercial Union gained 11p to 631p; General Accident 9p to 625p and Royal Insurance 2p to 324p.
Tiphook, the container group, remained under pressure, falling 21p to 230p. Talk of lower German interest rates lifted Redland, the building materials group, 13p to 481p. Spring Ram gained 4p to 54p. Talk that MB Caradon may bid has been dismissed.
Great Universal Stores made further progress with weekend talk that the mail order group's pounds 1.5bn cash pile might be distributed among shareholders, adding to the tide of approval produced by last week's greater exposure and enfranchisement. The voting shares rose 90p to 3,490p and the 'A' shares 47p to 1,957p.
Forte rose 7p to 229p on the possible sale of its Harvester pub and restaurant chain.
J Sainsbury continued to lead the food retailers' revival. The shares jumped 16p to 458p, a two-day gain of 31p. Asda put on 2.5p to 62.5p; Argyll 5p to 313p and Tesco 9p to 209p. But Kwik Save shaded 4p to 677p.
Budgens held at 44p as the German retail group REWE picked up 350,000 shares, lifting its stake to 27.02 per cent. Court Cavendish, the nursing homes group, continued to suffer. The shares retreated further from last week's 225p flotation level, closing 11p lower at 185p.
Dalepak Food, which reported sharply lower profits last week, slumped 31p to 154p after nervous but scattered selling.
UK Land, the struggling property group, had the distinction of being the day's main casualty, outperforming even Medeva.
The shares crashed 26p to 4p. Late on Friday the company, which owns the Elephant and Castle shopping centre, unveiled plans for a voluntary arrangement, a capital reconstruction and a cash-raising exercise.
The FT-SE 100 index, at one time showing signs of moving strongly ahead, ended 9.9 points up at 2,842.9 with the FT-SE 250 index down 6.2 at 3,211.3. Turnover was 760.4 million with 34,743 bargains. The account ends on 30 July with settlement on 9 August.
Bensons Crisps gained 4p to 76p. Interim results are due soon and are expected to show a loss. But, despite the fierce price war in the snack food industry, Bensons should produce year's profits in line with 1992's pounds 500,000. A new factory due to open in the spring should help to reduce overheads and put Bensons in a better position to combat price cuts by its bigger rivals.
TSB, the banking group, closed for the first time above 200p. The market is growing increasingly convinced that the long-rumoured sale of the troubled Hill Samuel merchant banking offshoot is nearing completion. The removal of HillSam could, it is argued, open the way for a takeover bid, with Lloyds Bank still seen by some as the most likely predator. TSB was up 4.5p to 303.5p.