Disappointing results from oil giants Chevron and Total hit BP Amoco, the newly-created giant ranking as Footsie's largest constituent, and Shell.
BP fell 16p to 841p and Shell 11.25p to 307.25p. Trading in both stocks was heavy.
The merger of BP and US group Amoco has helped support the enlarged group's shares, giving the impression of relative strength.
Many tracker funds had to pile into BP to maintain their portfolio balance when its size ballooned following the Amoco deal.
But poor old Shell, rumoured to be seeking a merger with a major oil group, has had no such luck. Its shares are at their lowest since 1996.
Last spring the price was 463.5p. And in 1997 it touched 484.5p.
Like other oil groups Shell has striven to cut costs. But any short-term fix for its shares would require determined corporate action. And that would mean, in the present bleak environment, a merger with another giant; in effect the two would cuddle together to keep warm.
The BP deal with Amoco prevents the integrated oil index from bumping along at a 1998/99 low but the exploration and production sector, despite the proposed Enterprise Oil/Lasmo merger, has no such protection.
Its shares were again deep in the dumps with Enterprise falling 2p to 225.5p, equalling a level last seen in 1987. Lasmo, which has drawn a little comfort from the feeling that it will draw some premium from any merger, held at a still hugely depressed 97.5p.
British Borneo, a shade firmer at 97.5p, is at its level of three years ago, and Premier Oil, off 1p at 13.5p, is another that has lost touch with its 90p peak.
Footsie fell 9.3 points to 5,876.4 in heavy trading with share turnover topping 1.2 billion. In early trading the index scored a 103 gain. Government stocks were little changed.
Much of the action was on the under-card with a round of takeover speculation among engineers sending the mid-cap index up 46.5 to 4,903.3 and the small- cap 7.8 to 2,102.8.
Both indices have been in the doldrums, reflecting the torture inflicted in the past seven months on medium and small companies.
Senior Engineering led the charge, up 13.5p to 119p. Besides any takeover element it drew strength from today's analysts meeting and a positive stance by ABN Amro.
Others on a speculative high included TI, up 30p to 350p, Morgan Crucible, 16p to 188.5p, and BBA, 25p at 385p.
Glynwed, one of Albert E Sharp's favourites, hardened 10.5p to 159p and Laird moved ahead 26.5p (after 40p) to 199p in busy trading.
Pilkington's, on its trading statement and confirmation of its Brazilian hit of around pounds 15m, rose 3p to 54p.
Reed International, the publisher, up 41.75p to 571.75p, caught the Internet buzz, seemingly on the back of developing 15 web sites for its various magazines.
Mirror, the newspaper publisher awaiting takeover action, hardened 2.5p to 211p.
Colt Telecom gained 46p to 1,276p, despite the emergence of a powerful US rival, Level3.
Rank, the out of favour leisure group, rose 8.5p (after 12p) to 203.5p on vague talk of executive appointments and, possibly, some corporate interest. The bombed out shares were 410p last year and 545p three years ago.
BTP, the chemical group, climbed 32p to 357.5p on BT Alex.Brown support and Vodafone, with ABN Amro forecasting a 1,600 price, improved 23p to 1,182.5p.
Capital, the casino operator, was shuffled 5.5p lower to 54p after bid talks were called off. But Primesight, a media group, added 24p to 283p as talks with a possible predator got under way. Wyndham Motor moved 5p ahead to 181p after Ryland emerged as the potential bidder.
Le Riche, a Channel Island stores group, plunged 85p to 410p following a profits warning and disappointing figures lowered Games Workshop, a computer games group, 47.5p to 397.5p.
National Grid and British Energy fell after regulator Callum McCarthy claimed electricity prices were too high. Grid dulled 14p to 495.5p and Energy 39p to 684.5p.
Kingfisher, with trading at is French unit triggering interest, gained 42p to 628p and Dixons was again on the march, up 53p to 1,029p.
Banks were ruffled by Brazil's problems and anxiety ahead of their profits season. Barclays fell 45p to 1,313p.
Arjo Wiggins Appleton, the paper and packaging group, firmed 3.5p to 103.5p after Warburg Dillon Read suggested a 137p break-up value.
Reflec, the reflective inks group, held at 4p ahead of an expected cash raising exercise, and Recognition Systems fell 3p to 12.75p after winning only 69 per cent take up for its 9p rights issue.
Systems Integrated, up 8.5p to 19.5p, said it could not explain the jump other than its return to profits. Three years ago the shares were 128p.
SEAQ VOLUME: 1.2bn
SEAQ TRADES: 69,500
DRAGON OIL flared 11.75p to 28p as small investors banked on the ruler of Dubai to revamp the group. Through Emirates National Oil Co, the Dubai government bid 15p a share and built a 69 per cent stake. With 31 per cent of the capital still in free hands, the Dragon share listing should be preserved. Emirates National says it is examining how best to develop Dragon's interests. The shares once topped 100p.
THE BITTER takeover bid battle for Blockleys, the building materials group, looks like being resolved at a specially called shareholders meeting.
Bidder Natural Building Materials (NBM) has called the meeting to vote on replacing three Blockleys directors with NBM men. Blockleys believes the bid will fail and sees the meeting as an attempt to win control through the backdoor. Blockleys shares held at 37.5p.