For much of yesterday's trading session it looked as if London's equity market measured by the FTSE 100 index had at last broken out of the strait jacket that has imprisoned the 100 index mostly in the 5,000 to 5,200 range since the beginning of October.

At its best of the day, in mid-morning, and celebrating an overnight upsurge on Wall Street, plus some encouraging domestic news, the FTSE 100 had driven confidently through its recent upside barrier of 5,286 and burst through the 5,300 level, eventually hitting a session high of 5,366.4.

It then ran into small pockets of turbulence and profit-taking which took the index back below 5,300.

But it was over the lunchtime period and running up to the opening of Wall Street when things went awry for the oil majors which carry heavy weightings in the FTSE 100 and drove the index down to finish the session with an unexpected decline.

The news which caused so much damage to BP and Shell, not to mention Enterprise Oil, came from the OPEC meeting in Vienna which saw producers agree to a cut in production of 1.5 million barrels a day, but only if non-OPEC producers agree to reduce output by 500,000 barrels a day. The market's view of the likelihood of that happening showed up instantly with oil shares plummeting and dragging the 100 index down with them.

Before the oil woes, the mood in London was more than hopeful after the continuing stream of news from Afghanistan, which saw the Dow Jones Industrial Average jump almost 200 points on Tuesday evening, accompanied by a similarly strong performance from the Nasdaq Composite.

There was plenty of economic and company news keeping the London market pot boiling as well.

The Bank of England's Quarterly Inflation Report pointed out the risks of inflation falling below the government's 1.5 per cent floor, while average earnings in the quarter to end-September, up 4.4 per cent year on year, came as no surprise to the market. Nor did the increase in unemployment.