MOBILE phone firm Vodafone helped the FTSE 100 Index return to positive territory yesterday after long-awaited confirmation of talks to sell its stake in US joint venture Verizon Wireless.

The heavyweight blue chip saw shares leap eight per cent higher, contributing most of the 0.8 per cent rise in the wider top tier, which closed 53 points higher at 6483.1.

Vodafone’s impressive share gains added to improved sentiment on world markets after two days of losses as the threat of imminent military action against Syria subsided.

Cheer over the US economy also provided a boost after revised figures showed growth of 2.5 per cent between April and June – much faster than the 1.7 per cent previous estimation.

The Dow Jones Industrial Average lifted more than 80 points in early trading as a separate report also showed that firsttime claims for unemployment benefits fell last week.

In currency markets, the pound remained higher against most major currencies except the dollar as it continued to benefit from upbeat comments by Bank of England governor Mark Carney.

Vodafone was the biggest riser in the FTSE 100 – up 15.5p to 204.8p.

Other big risers included advertising and marketing firm WPP, up 49p to 1227p after it raised its full-year outlook on the back of improving demand in the UK and US.

The fallers board was topped by outsourcing services firm Serco after it emerged that the Government had uncovered potentially fraudulent behaviour in the management of its £285m prison escorting contract. Shares fell 11 per cent or 68p to 538.5p.

Other fallers were Antofagasta off 25.5p to 849p, Pearson 36p lower at 1280p and Vedanta Resources down 22p at 1187p.