* FTSE 100 down 0.7 pct at close
* Sterling rallies after EU's Barnier offers close ties
* Shares in oil producers, consumer stocks weigh
* Aston Martin plans IPO(Recasts, adds quote and detail, updates prices at close)
By Kit Rees
LONDON, Aug 29 (Reuters) - The UK's top share index slid onWednesday, under pressure from a bounce in the pound on the backof remarks from the European Union's chief negotiator MichelBarnier, who offered Britain close ties after Brexit.
The blue chip FTSE 100 index ended the session down0.7 percent at 7,563.21 points, underperforming a broadlypositive European equity markets.
The EU's Barnier said that the bloc was prepared to offerBritain a partnership, though no "single market a la carte",which sent sterling soaring.
"Barnier’s comments are clearly positive for the Brexitnegotiations and indicates that we are about to get some sort ofdeal before the end of the year," Neil Wilson, chief marketanalyst for Markets.com, said.
The FTSE tends to come under pressure from a strongerdomestic currency, given that a sizeable chunk of itsconstituents earn revenues in dollars.
Stocks in the consumer staples sector came under particularpressure, with shares in British American Tobacco andDiageo down 1.4 percent and 0.4 percent respectively.
Shares in UK-listed oil and gas firms took the most pointsoff the index, with BP and Royal Dutch Shellboth down around 1 percent.
Shares in mining companies were also on the backfoot asworries over Chinese demand and a stronger dollar hit the priceof London copper.
Glencore, Rio Tinto BHP Billitonand Anglo American all retreated between 0.7 to 1.8percent.
The mood in markets more broadly was cautious, however, asoptimism faded over a proposed trade deal between the UnitedStates and Mexico given that questions remain over whetherCanada will also agree to the revised trade terms.
A looming deadline on U.S. tariffs with China also keptmarkets on edge.
"There is still a little optimism doing the rounds in lightof the U.S.-Mexico trade deal, but investors haven’t been givenanother reason to buy into the market," David Madden, marketanalyst at CMC Markets UK, said.
The UK's mid cap index was also subdued, trading 0.5percent lower.
In a sign of confidence, however, luxury carmaker AstonMartin set out plans to float on the London Stock Exchange,hoping to complete the flotation this year.
"The brand strength is unquestionable but at the end of theday some investors will only want to get involved if thebusiness can sell more units than it did in the previous yearand at a higher price, and continue this trend ad infinitum,"said Russ Mould, investment director at AJ Bell.(Editing by Andrew Bolton)
