FTSE 250: 4,722.9 (+50.6); FTSE SmallCap: 2,000.9 (+5.1)Behind a dramatic late revival of sentiment in the leaders was a big US-inspired swing in many of the super-heavyweight sectors, such as banks, oils and pharmaceuticals.

The US support for those areas came after Wall Street staged a strong rally, the Dow Jones Industrial Average recouping an initial 135 points slide to trade up on balance as the London trading session ended.

Wall Street's recovery came after second-quarter productivity data, which, although well below the pace of the first quarter, was nevertheless better than the market had been going for.

Prior to the late recovery, the FTSE 100 index had blown hot and cold, an initial upsurge, triggered by events on Wall Street on Thursday evening, foundering in the face of fresh pockets of profit-taking.

Dealers said London's mid-morning stutter came in the wake of worse global trade figures than expected.

But while the FTSE 100 succumbed to the various storms prior to its late flourish, the broader market, represented by the FTSE 250 and SmallCap indices, made strong progress for the third consecutive session, underscoring the generally improved mood in the market during the week.

Fair value for the FTSE future expiring on September 20th was estimated at a discount of 10.98 to the cash market.

The Footsie's latest move came after technical analysts said the 4,280 level would prove crucial.

Mr David Franklin, director of retail funds at Christows, the private client portfolio manager, said: "Getting through 4,280 is critical to a continuation of the recovery. If the index drops back below 4,280, it is likely to remain rangebound between that level and support at 4,020. If it can gather enough energy to hold above 4,280, the next target level lies in the range 4,698 to 4,966."

Turnover in equities was 1.97 billion shares and was boosted late in the day by programme trade activity. - (Financial Times Service)