(For a Reuters live blog on U.S., UK and European stock markets, click LIVE/ or type LIVE/ in a news window) * All eyes on U.S. presidential election race * Differences remain with UK on Brexit deal - EU negotiator * Provident Financial jumps on upbeat 2020 outlook * FTSE 100 up 1.7%, FTSE 250 adds 1.7% (Adds comment; updates to close) Nov 4 (Reuters) - London’s FTSE 100 jumped on Wednesday as a weaker pound boosted shares of exporters, although investors remained cautious on prospects of a contested outcome as the race to White House headed for a photo-finish. After falling nearly 1.3% in the morning trade, the blue-chip FTSE 100 index closed 1.7% higher in a volatile session, boosted by dollar earners such as AstraZeneca Plc, Experian Plc and Rentokil Initial Plc . Bank and mining stocks fell after leading a surge earlier this week on bets that a decisive Democratic victory could pave the way for more economic stimulus. The excruciatingly close U.S. presidential election hung in the balance, with a handful of closely contested states set to decide the outcome in the coming hours or days, even as President Donald Trump falsely claimed victory and made unsubstantiated allegations of electoral fraud. “The risks of a protracted contested election outcome appear significant and the market is likely to be most concerned by genuine uncertainty on the vote margin rather than political uncertainty relating to a refusal to concede,” Deutsche Bank currency analyst George Saravelos said. “The margins on numerous key states are very narrow or uncertain leading to a risk of protracted recount and litigation battles”. The mid-cap FTSE 250 ended 1.7% higher even as European Union’s negotiator told EU envoys that differences remained on key issues with Britain on Brexit-trade deal. Separately, financial data company IHS Markit said Britain was heading for double-dip recession this winter as business surveys show economic growth almost halted last month even before the latest England-wide lockdown was announced. Investors now looked forward to the Bank of England monetary policy meeting on Thursday morning at 0700 GMT. Provident Financial Plc rose 5%, after the doorstep lender said collection performance in its home credit business has now aligned with pre-pandemic levels, with the company set to meet market expectations for this year. Marks & Spencer Group Plc gained 4.9%, after the retailer posted a smaller-than-expected loss for the first half. (Reporting by Devik Jain in Bengaluru; Editing by Shailesh Kuber, Anil D’Silva and Sandra Maler)