Britain's blue chip FTSE 100 index rose 0.5 percent to 7,364.05 points, outperforming a negative European market thanks to a weaker sterling, down 0.4 percent on the day.
Large dollar-earning firms, for whom a weaker sterling/dollar exchange rate boosts earnings, were top gainers, with British American Tobacco, Imperial Brands, Diageo and Unilever rising 1.9 to 4.1 percent.
Whitbread was a late riser to the top of the FTSE, shooting up 7.8 percent after U.S. activist investor Sachem Head revealed a stake in the Costa coffee owner.
Tracking weakness in the broader European market, financials took nearly 6 points off the index, with shares in HSBC, Lloyds and Barclays up to 0.8 percent lower as enthusiasm over U.S. tax reform, which had boosted lenders in the past week, dissipated.
Jitters in tech drove Micro Focus and WorldPay down.
Mid-cap cybersecurity firm Sophos, which has been the best-performing FTSE 250 stock this year, up a cool 105 percent, also tumbled 3.7 percent as investors shunned highly-valued tech stocks.
DEAL OR NO DEAL?
Investors' eyes were glued to developments in fraught Brexit negotiations which have caused swings in sterling.
"Whether or not there is 'sufficient progress' on Brexit divorce talks by the EU Council Summit on 14/15 December is key to our economic outlook," said Bank of America Merrill Lynch strategists in a note.
Irish Prime Minister Leo Varadkar said negotiations over how Brexit would change sensitive Northern Irish border arrangements could pick up again in the new year if a deal was not made this week.
British press reports no such deal would be reached sent sterling down on Wednesday.
Deal-making, of the corporate kind, also added some spice at the single-stock level.
Shares in Hammerson fell 6.1 percent to the bottom of the FTSE after the real estate investment firm said it would buy shopping centre operator Intu Properties (>> Intu Properties), revealing investors' anxieties about value creation in a difficult environment for commercial real estate.[nL8N1O6146]
"Shareholders will want to see assets sold down in the merged company to help fund the deal and to reflect the lower demand for brick and mortar stores," said LCG's Jasper Lawler.
Shares in Intu Properties, however, leapt 15 percent and were on track for their biggest one-day gain on record. Intu's shares were down almost 30 percent ahead of the announcement.
Stifel analysts were more upbeat on the deal: "We think the market will welcome an enlarged REIT which will be... more meaningful from a global perspective for REIT investors."
Among other standout movers, shares in travel group Saga (>> Saga) dropped 24.8 percent after a profit warning.
(Reporting by Kit Rees and Helen Reid; Editing by Hugh Lawson and Toby Davis)
By Kit Rees and Helen Reid
Stocks treated in this article : Lloyds Banking Group
, BHP Billiton Plc
, Intu Properties
, BHP Billiton Limited
, British Land
, Rio Tinto
, HSBC Holdings
, Sophos Ltd
, Worldpay Group
, Micro Focus International plc
, Land Securities Group plc