European shares hit new three-month low, GAM slumps 15 pct

LONDON, June 14 (Reuters) - European shares fell for a fifth straight session to a new three-month low, led down by commodities stocks, with investors becoming jittery before the U.S (Other OTC: UBGXF - news) . Federal Reserve's policy meeting and next week's EU referendum in Britain.

The pan-European FTSEurofirst 300 index dropped 1 percent to its lowest level since late February, while the broader STOXX Europe 600 index also fell 1.1 percent.

European basic resources and oil and gas indexes fell 2.4 percent and 1.5 percent respectively, tracking weaker commodities prices.

Swiss money manager GAM Holding (LSE: 0QN3.L - news) fell nearly 15 percent to a 4-1/2 year low after warning it expects a roughly 50 percent year-on-year fall in first-half underlying profit before tax, mainly due to lower performance fees.

However, shares in Premier Farnell (LSE: PFL.L - news) surged 48 percent after Daetwyler Holding agreed to buy Premier Farnell in an all-cash offer that valued the British electronic component distributor at just over 1 billion Swiss francs ($1.04 billion).

Two opinion polls published by ICM showed on Monday that Britain's "Out" campaign had widened its lead over the "In" camp ahead of the June 23 referendum on Britain's EU membership, adding to investors' general nervousness.

Uncertainty over this week's two-day Fed meeting, starting later in the day, also weighed on markets, though the U.S. central bank is widely expected to leave rates unchanged after the much weaker-than-expected May nonfarm payrolls report.

(Reporting by Atul Prakash; Editing by Sudip Kar-Gupta)