The blue-chip FTSE 100 index <.FTSE> initially rose to an all-time high of 7,119.35 points but then edged back. The index was down 0.3 percent at 7,078.92 points going into the close of trading.

Pearson fell 3.6 percent, one of the worst performers on the FTSE, after the Los Angeles Times reported that the Los Angeles Unified School District was seeking a refund from Apple over a bungled $1.3 billion effort to supply students with iPads.

The district's initiative, launched in 2013, to equip each of its roughly 650,000 students with an iPad or another computer device with curriculum material from Pearson, was the largest educational technology project of its kind in the United States.

Diageo, the world's largest spirits maker, fell 3 percent after it reported lower quarterly sales.

The FTSE has hit a series of record highs this month despite political uncertainty before Britain's general election on May 7, which has hit sterling .

Opinion polls put the governing Conservatives neck-and-neck with the opposition Labour party, and the Scottish National Party may emerge as the third-biggest party, raising prospects of a hung parliament.

The Conservatives have promised a referendum on Britain's membership of the European Union by the end of 2017, if they win.

Some traders have said the FTSE has managed to rise against that backdrop since the weakness in sterling could help British exporters, but Beaufort Securities' sales trader Basil Petrides was more cautious.

"I'm not willing to buy into the market at these levels with the election just around the corner," he said.

UNILEVER, GOLD MINERS RISE

Consumer goods group Unilever rose 2.8 percent after better-than-expected sales.

Precious metal miners Randgold and Fresnillo also advanced as gold extended gains after sluggish U.S. data weakened the dollar. A weaker dollar makes gold cheaper for holders of other currencies, and more attractive as a hedge against economic downturn. [GOL/]

InterTrader's chief market strategist Steve Ruffley said the FTSE could rise to 7,300 points over the coming month.

"The outcome will most likely be a Conservative coalition. Immediately after the election, we will probably sell off but any major sell-off will be bought back very quickly."

(Additional reporting by Alasdair Pal and Alistair Smout; Editing by Crispian Balmer and John Stonestreet)

By Sudip Kar-Gupta