By Sara Sjolin, MarketWatch

NEW YORK (MarketWatch) -- The U.K.'s FTSE 100 index moved slightly lower on Monday, with shares of oil companies falling alongside weaker energy prices and investors remaining concerned about the Scottish independence vote.

The benchmark fell 0.1% to 6,800.94. Last week, the FTSE broke a four-week winning streak and dropped 0.7% amid concerns Scotland might vote to leave the U.K. at the referendum on Sept. 18.

Over the weekend, Scotland's first minister and leader of the pro-independence Scottish National Party Alex Salmond asked voters to grasp a "once in a lifetime" opportunity and vote for independence. Polls leading up to the vote have been neck to neck, stirring uncertainty in the financial markets. Particularly the pound (GBPUSD) has been beaten down and continued lower on Monday to trade at $1.6233, from $1.6265 late Friday.

Movers: Oil firms added the most pressure on the London benchmark on Monday, with shares of BP PLC (BP) down 1%, BG Group PLC 1.9% lower and Royal Dutch Shell PLC (RDSB) off 0.6%. The losses came as oil prices moved lower after weak Chinese industrial data over the weekend.

Shares of SABMiller PLC (SBMRY) climbed to the top of the FTSE, up 8.7%, after news that Anheuser-Busch InBev NV(AHBIY) is talking to banks about financing a deal to buy the London-listed brewer.

TUI Travel PLC added 1.9% after the travel operator and its German parent TUI AG agreed on the terms of their all-share merger, originally announced in June.

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