Britain's FTSE retreats as pharma stocks fall

* FTSE 100 down 0.3 pct

* Pharma stocks down after Clinton's EpiPen comments

* Glencore (Frankfurt: 8GC.F - news) leads miners lower

* CRH (EUREX: 558474.EX - news) rises after results (ADVISORY- Follow European and UK stock markets in real time on the Reuters Live Markets blog on Eikon, see cpurl://apps.cp./cms/?pageId=livemarkets)

By Kit Rees and Alistair Smout

LONDON, Aug 25 (Reuters) - UK shares fell on Thursday, extending losses from the previous session as healthcare stocks dropped, though CRH rose after well-received results.

The blue-chip FTSE 100 index was down 0.3 percent at 6,816.90 points by the close. It outperformed European peers, benefitting from sterling weakness against the euro.

Healthcare stocks were a major weight on the FTSE 100, with Hikma, Shire (Xetra: S7E.DE - news) and Astrazeneca (NYSE: AZN - news) falling between 1.4 percent to 3.5 percent.

That mirrored losses on Wall Street made on Wednesday after Democratic presidential nominee Hillary Clinton called for a lower price for Mylan NV's allergy drug EpiPen, which has become four times more expensive in the past decade.

"(This) ... serves to strike fear into the hearts of healthcare groups and their investors everywhere," Mike van Dulken, head of research at Accendo Markets, said in a note.

"The industry (is) ... treading the fine line between balancing the costs of clinical success (and failure) with the economic laws of supply and demand."

A weak copper price, which remained near a two-month low, weighed on the mining sector which was down 0.9 percent.

Glencore fell 2.6 percent, extending losses from the previous session when it posted a drop in first half earnings.

Among the top risers, construction firm CRH gained 2.9 percent after well-received results, hiking its dividend for the first time in seven years.

CRH was the most heavily traded stock on the FTSE 100, attracting nearly twice its 90 day average volume. The FTSE 100 as a whole saw just 70 percent of its daily average trade.

Advertising group WPP (Frankfurt: A1J2BZ - news) extended its rally from the previous session, up 1.3 percent after a spate of broker price target upgrades on the stock following results on Wednesday.

"We think WPP should be a core holding for long-term investors," analysts at Barclays (LSE: BARC.L - news) said in a note.

Outside the blue-chips, gambling technology company Playtech hit a record high earlier in the session, rising 3.2 percent. It announced a special dividend after reporting an 18 percent jump in first-half revenue.

Greg Johnson, analyst at Shore Capital Markets, said in a note that the stock was very cheap for the strong revenue growth it delivered.

Carillion (Frankfurt: 924047 - news) dropped 4.9 percent, away from a five month high hit in the previous session following its results, after it was downgraded to "underweight" from "neutral" by JP Morgan.

Food delivery firm Just Eat (Frankfurt: A1100K - news) also suffered from a downgrade, falling 4.1 percent after being cut to "equal weight" from "overweight" by Barclays.