The festive rally for London's FTSE 100 Index extended to a seventh session today after investors were given a lift by bumper US growth figures.

A shortened trading session finished with the FTSE 100 Index up 11.75 points at 6609.9 after the Dow Jones Industrial Average closed above the 18,000 barrier for the first time on Tuesday night.

The latest milestone on Wall Street came as the world's biggest economy recorded annualised growth of 5% for the third quarter of the year.

The FTSE 100 Index is still more than 300 points short of its own all-time high after big losses at the start of the month. However, the top flight index has rallied in recent days amid thin festive trading volumes.

The pound was little moved against the US dollar after slipping to its lowest level for 16 months at 1.55, driven lower by downward revisions to recent UK growth figures. Sterling was flat against the euro at 1.27.

Takeover speculation helped fuel some buying interest during the London stock market's last session until Monday.

Shares in replacement hip and knee firm Smith & Nephew jumped 8% on reports that US rival Stryker is planning a takeover of the company valued at £10.5 billion.

Talk of Stryker's interest in the FTSE 100 business has come up before, and in May the US firm was forced to issue a statement saying it was not bidding for the UK firm. Under Takeover Panel rules this formally precluded it from making a bid for Smith & Nephew for six months.

Hull-based Smith & Nephew, which employs 11,000 staff in more than 90 countries, rose 84p at 1173p.

Other risers included stocks in the retail sector after estimates from the Department for Business, Innovation and Skills pointed to a record year for the UK high street, with retail sales forecast to reach around £342 billion.

The figures, which come amid signs of a strong festive period for retailers, helped beleaguered supermarket stock Tesco rise by 1.4p to 186p. Rival Morrisons was 1.3p higher at 181.7p.

Other risers included oil giant BP, which was up by a penny at 416.85p, and broadcaster ITV with a gain of 2.1p to 216.2p.

The biggest faller was FTSE 100 newcomer Indivior as some of the excitement surrounding its strong market debut began to fade.

The pharmaceuticals business, which focuses on drugs to fight alcohol and cocaine addiction, surged 25% on the first day of trading since its split from Reckitt Benckiser. The stock was down 3% or 5p to 145p today.

The biggest FTSE 100 risers were Smith & Nephew up 84p at 1173p, ITV ahead 2.1p at 216.2p, Royal Bank of Scotland up 3.7p at 394.9p and AstraZeneca ahead 39p at 4555.5p.

The biggest fallers were Indivior down 5p at 145p, Randgold Resources off 87p at 4153p, Shire down 63p at 4470p and BHP Billiton off 13.5p at 1369p.