London's FTSE 100 fell on Monday with industrial miners leading declines, tracking weakness in global equities on caution ahead of a US Federal Reserve meeting later this week, while gains in Vodafone and Unilever helped limit losses.

The blue-chip FTSE 100 index fell 0.8% with miners Glencore, Anglo American and Rio Tinto the biggest drags, while Vodafone and Unilever were the top gainers.

Unilever jumped 6% to the top of the FTSE 100 after Trian Partners, Nelson Peltz's activist hedge fund, built up a stake in the consumer goods maker, a person familiar with the matter told Reuters on Sunday.

Vodafone jumped 5.2% after sources said it was in talks with telecom peer Iliad to strike a merger deal in Italy.

The domestically-focussed midcap index dropped 1.5% to its lowest in six-months, pushed lower by weakness in travel and leisure stocks.

Miners drag FTSE 100 lower with BHP set to exit index

Markets globally have turned cautious ahead of a Fed meeting due later this week at which it is expected to confirm it will soon start draining the massive lake of liquidity that has supercharged growth stocks in recent years.

"The broader bearish sentiment has really taken off ahead of the Fed meeting, with definite bets of a rate hike in March, and investors now looking to figure out if there will be three or four hikes this year," said David Madden, market analyst at Equiti Capital.

The FTSE 100 is set to drop for the third straight session, while still outperforming the wider STOXX 600 index as rising crude prices helped support heavyweight energy shares and cheaper valuations maintained investor interest in UK equities.

The rising tensions between Russia and Ukraine have affected wider risk sentiment, but it could be a positive for UK equities in the near term as escalations could push oil prices higher, Madden added.

Events organiser Informa fell 2.4% on plans to auction its clinical trial data provider Citeline at a possible valuation of 1.2 billion pounds ($1.63 billion), sources told Reuters.