Shares in British Airways owner International Airlines Group took flight as the group posted soaring quarterly profits, amid turbulence on the wider market that eventually saw blue-chip shares enjoying a positive close to the week.

IAG was up 8% after BA reported a "bounceback" following last year's London Olympic Games impact which had slashed demand for business flights from the capital.

A topsy-turvy session on the FTSE-100 Index saw it close 11.2 points ahead at 6708.4 after falling earlier on the back of big overnight Wall Street losses and a downgrade for France's credit rating.

Initially adding to jitters was better-than-expected American jobs data resulting in the now familiar worries about whether it would mean the US Federal Reserve's quantitative easing programme being tapered sooner rather than later.

But this eventually gave way to hopes that the better news for the economy could open up the possibility over a rosier scenario where the Fed's help may not be needed any more.

In Germany, the Dax was flat and France, preoccupied by its own woes, saw the CAC 40 fall. It came as France's sovereign debt rating was cut one notch to AA by S&P.

On currency markets, the improved hopes for the US economy saw sterling down one cent against the dollar to 1.60 US dollars and flat against the euro at 1.20 euros.

In London, the enthusiasm from across the Atlantic was somewhat dampened by a sharp downgrade for construction sector growth for the third quarter from 2.5% to 1.7%, while the UK goods trade deficit with the EU reached a record high.

But there was a warm welcome for theme park operator Merlin Entertainments, with shares starting conditional dealings up 7% to 347p, having been priced near the top end of expectations at 315p. In corporate news, IAG shares rose 27.9p to 376.9p after a "strong" July to September period helped pre-tax profits jump to €606 million (£505 million) from €244m a year earlier. The results were boosted by a €100m (£83m) sales jump at BA after the Olympics hit in 2012.

IAG cited strong demand for transatlantic flights and growth in the London market, with positive sentiment also helping budget carrier easyJet rise 25p to 1225p.

Shares in Rolls-Royce also made decent gains on the blue chip index, rising 40p to 1210p, as the jet engine maker said it remains on track for strong annual profits growth.

The biggest FTSE 100 risers were International Airlines Group, Rolls-Royce, Persimmon, up 25p to 1197p and easyJet.

The biggest fallers were Aberdeen Asset Management, down 20.2p to 422.2p, Randgold Resources, down 150p to 4735p, ARM Holdings, down 23p to 941p and William Hill, down 9p to 385.4p.