FTSE 100 movers: Weir Group receives worrying forecast, Royal Mail continues to plummet

Share prices in Weir Group took a hit after Investec slashed its target price for the industrial engineering group by 17%, from 1,900p to 1,585p. The broker said that almost every important data point for the company is "trending negatively" and reiterated its 'sell' recommendation to clients. Investec estimates that falling commodity prices - oil, gas and iron ore - will have a big impact on volumes for Weir.

Postal group Royal Mail was also trading in the red after both Credit Suisse and Jefferies reiterated their 'underperform' ratings on the stock.

Accountancy software group Sage was a strong riser after it hailed higher annual profits and the achievement of key financial milestones for 2014. The company also said it was on track to hit financial targets for 2015.

ARM Holdings saw prices rise after RBC Capital reiterated an 'outperform' rating in a research report released on Wednesday morning. This follows Numis Securities’ restated 'buy' rating on the shares, released on Monday.

Stocks in the oil sector were pulling back after a solid rise, causing shares in Tullow Oil to dip. Barclays said in a research note that oil producers across Europe can expect a "material squeeze" in cash flows and earnings next year because of the recent slump in oil prices and reduced its 2015 earnings estimates for the sector by an average 20%.