FTSE down 1 pct as miners, M&S fall; pharmas rise

*FTSE 100 ends down 1 pct

*Miners fall on weaker coal prices

*AstraZeneca surges after U.S. patent ruling

*M&S slumps after shock warning on profit

By Dominic Lau

LONDON, July 2 (Reuters) - Britain's top share index shed 1 percent on Wednesday, extending the previous session's sharp losses as miners fell on weaker coal prices and Marks & Spencer (MKS.L: Quote, Profile, Research) slumped after a profit warning, though drugmakers rose.

The FTSE 100 .FTSE closed down 53.6 points at 5,426.3 to touch a three-month low in a volatile session after trading as much as 1.6 percent higher. On Tuesday, the UK benchmark index lost 2.6 percent.

"It's good to see pharmaceuticals are finally doing what they should be and that's offering a bit of defensive solace. But other than that I am not particularly optimistic about the short-term position," said Tim Whitehead, head of portfolio services at Redmayne-Bentley.