* FTSE 100 down 0.5 pct
* Narrow weekly gain on more dovish Fed tone
* AstraZeneca slide continues as co declines comment
* Derwent London rises on Exane's real estate optimism
* Carillion sees relief as appoints financial adviser (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)
LONDON, July 14 (Reuters) - Britain's major share index faltered on Friday, cutting its weekly gain from a global rally after U.S. Fed officials hinted monetary policy tightening would go ahead at a slower pace.
The FTSE 100 fell 0.5 percent, underperforming mid-caps and taking weekly gains to a narrow 0.2 percent.
The more defensives-heavy index suffers when expectations of monetary policy tightening dampen. European stocks on the other hand enjoyed their best week in more than two months.
Defensive housebuilding stocks such as Barratt Development and Persimmon were among the top blue-chip fallers.
Drugmaker AstraZeneca continued Thursday's slide, down 1.6 percent due to uncertainty around reports that CEO Pascal Soriot was preparing to leave the company.
As spokespeople declined to comment on the report, the combined two-day share drop wiped more than 3 billion pounds off Astra's market value.
Firmer metals prices underpinned gains on mining stocks, with Anglo American and Fresnillo top of the blue-chips.
Anglo American, with considerable South Africa exposure, also benefited from the country suspending implementation of a new mining law which analysts had said could negatively impact firms.
Royal Mail shares fell 2.4 percent after it replaced its pension plan, giving employees a choice between defined benefit or contribution pension scheme after opposition from trade unions.
Among mid-caps, Carillion saw a small relief bounce from heavy losses this week, rising 1.3 percent after the crisis-hit construction and support services contractor hired HSBC as joint financial adviser and corporate broker, amid speculation it is preparing a rights issue.
Despite the slight relief, the firm was left with 70 percent less market value than at the start of the week. "A lot of our clients cut their positions on the first day and we haven't seen further flows in the stock after that," said a trader.
Property firm Derwent London was among top European gainers, up 3.4 percent after Exane BNP Paribas raised the stock to an "outperform" rating, citing the firm's "defensive" rents and strong pipeline. It expressed optimism about the prospects for a sector seen as particularly vulnerable to Brexit.
"Values in the London office market have barely moved post-Brexit thanks to abundant investment market liquidity (particularly from Asia) and resilient take-up," its analysts said in a note, adding that firms have recycled capital, deleveraged and payed special dividends.
Exane analysts forecast an average 8 percent decline in London office rents by 2019 - "a gradual weakening rather than a sharp correction", as they put it.
Emerging markets-focused asset manager Ashmore fell after reporting a 5 percent rise in its fourth-quarter assets, boosted by new client cash. Despite the results being in line with forecasts, the shares slid 2.2 percent to the bottom of the mid-caps.
"This was Ashmore's second consecutive quarter of inflows, marking the first time since 2013," UBS analysts said in a note.
"That said, due to the increase in the GBP/USD rate during the quarter, the growth of assets under management measured in sterling was a more moderate 1.1 percent quarter-on-quarter." (Reporting by Helen Reid; Editing by Jon Boyle)