A WARNING of "significantly lower" fourth quarter profits from oil giant Royal Dutch Shell sent shares lower, but the wider top-flight gained ground following buoyant Christmas retail figures.

It was an uncomfortable start to the tenure of new boss Ben van Beurden, who admitted the performance was "not what I expect from Shell" just two weeks after succeeding Peter Voser as chief executive.

Shares fell 1% on the update but the wider FTSE 100 Index was 13.9 points ahead at 6829.3 thanks to retail sales figures that were far above expectations.

The Office for National Statistics said sales leapt 2.6% higher month-on-month in December -against forecasts of 0.2% - and jumped 5.3% year-on-year, the best performance for more than nine years.

The FTSE 100 is now edging close to the 6840.3 figure that was the highest reached last year. That was the best end-of-day number for the top-flight since an all-time high reached on December 30 1999.

In New York, the Dow Jones Industrial Average was ahead after a mixed bag of economic data - with factory output up for a fifth straight month but a slowdown in construction during December. Bourses in France and Germany were up too.

On currency markets, sterling was buoyed by the UK retail sales data, climbing one cent to 1.64 US dollars and a cent against the single currency to 1.21 euros.

But in London, progress was held back by falls from heavyweight stock Shell, which said a range of factors and writedowns were expected to see fourth quarter earnings plunge 70% and full year earnings drop 38%.

Shell blamed higher exploration costs and ongoing refining woes for the poor end to its year.

Its shares dropped 26.5p to 2279.5p, while rival BP recovered from heavy early session losses to stand 1.6p higher at 491p.

Bookmaker William Hill led the top tier fallers' board after its trading update revealed a £13 million hit from the sector's hammering last week when the top seven Premier League football teams all secured victories for the first time. Shares fell 3% or 12.6p to 360.1p.

Rival Ladbrokes dropped 5% in the FTSE 250, down 9p to 167p.

Meanwhile, Royal Bank of Scotland was another top-flight loser as the Financial Conduct Authority outlined details about how its probe into the state-backed group would take shape.

It follows damaging allegations about its small business customers being driven to the wall to boost the bank's profits. Shares fell 2%, or 7.8p, to 363.7p.

The biggest FTSE 100 risers were Admiral, up 81p to 1407p, Glencore Xstrata up 11p to 338.2p, Hammerson up 13p to 518p and Land Securities up 22p to 1030p.

The biggest FTSE 100 fallers were William Hill, down 12.6p to 360.1p, Aberdeen Asset Management down 12p to 439p, Royal Bank of Scotland and ITV down 3.9p to 203.2p.