(ShareCast News) - London's FTSE 100 was up 1% to 6,116 at 1423 BST in a choppy session as stocks rebounded from weakness on Tuesday.Industrial equipment rental firm Ashtead was the standout gainer after it posted better-than-expected first quarter pre-tax profits of £155m, up 23%, driven by solid revenue growth in the US and UK. Chief executive Geoff Drabble said the strong numbers reflected the company's diversification strategy, with its US Sunbelt arm delivering a 23% increase in revenue and its UK division also performing strongly.Hikma Pharmaceuticals was on the up after Barclays lifted its price target on the stock to 2,760p from 2,050p.The bank said Hikma has transformed its US exposure and long-term visibility through the $2.65bn acquisition of US specialty generics company Roxane. "The closure of the deal transforms Hikma's presence in the US, its long-term growth trajectory, and the reliance on shortage drug opportunities," said Barclays.Satellite telecoms group Inmarsat continued to gain following the successful launch into orbit of its I-5 F3 Global Xpress satellite.Chip maker ARM Holdings was also a higher riser after JPMorgan Cazenove upgraded the stock to 'neutral' from 'underweight' and kept its price target at 850p. "With ARM stock having corrected since the beginning of July, we believe the stock is discounting the impact of the smartphone correction even though consensus estimates likely remain too high."AstraZeneca also got a boost from a broker note, as HSBC lifted its stance on the pharmaceuticals giant to 'buy' from 'hold' on share price weakness and ahead of oncology news flow. It noted that the shares have fallen 8% since the beginning of August and 16% since the year's highs in April. It attributed the decline in the short term more to global market volatility than any fundamental issues with the stock.British Airways owner International Consolidated Airlines Group gained after announcing that its offer for Aer Lingus is closed and it now controls 98.05% of the Irish carrier. IAG said that Aer Lingus shareholders who accepted the offer will receive payment for their shares within 14 days. This includes Ryanair, which had a nearly 30% stake in the carrier and the Irish government, which owned 25.1%.On the downside, Glencore slid as metals prices declined across the board with the exception of tin, while BP dropped amid extreme volatility in oil markets.RisersAshtead Group (AHT) 961.50p +4.85%Hikma Pharmaceuticals (HIK) 2,312.00p +3.91%3i Group (III) 473.90p +3.20%Inmarsat (ISAT) 991.50p +2.59%BHP Billiton (BLT) 1,079.00p +2.18%ARM Holdings (ARM) 930.00p +1.81%International Consolidated Airlines Group SA (CDI) (IAG) 537.50p +1.80%Mondi (MNDI) 1,442.00p +1.76%Intu Properties (INTU) 320.00p +1.59%AstraZeneca (AZN) 4,094.50p +1.51% FallersGlencore (GLEN) 126.60p -5.17%BP (BP.) 344.00p -1.55%G4S (GFS) 248.40p -1.35%Standard Chartered (STAN) 715.20p -1.24%Sainsbury (J) (SBRY) 235.00p -1.22%Royal Dutch Shell 'B' (RDSB) 1,626.50p -1.18%Royal Dutch Shell 'A' (RDSA) 1,619.50p -1.13%Randgold Resources Ltd. (RRS) 3,891.00p -0.89%Pearson (PSON) 1,083.00p -0.82%British American Tobacco (BATS) 3,366.50p -0.72%