UK shares are largely flat despite a swathe of corporate announcements on Monday. The FTSE 100 slips a barely noticeable 10 points lower to 6,570, although midcaps again suffer more harsh treatment from investors. The FTSE 250 index slumps more than 1090 points, or 0.6%, to 17,392.

Theme park operator Merlin Entertainments (MERL) tumbles 4.6% to 403.8p after warning the high profile rollercoaster crash at Alton Towers has had an adverse impact on trading at the start of the 'critical' summer period and on the board's expectations for the full year. Full year EBITDA (earnings before interest, tax, depreciation and amortisation) for the resort theme parks division is expected to be between £40 million and £50 million compared with £87 million in 2014. Better than expected financing costs of between £40 million and £45 million mean the overall group's underlying pre-tax profit will be broadly in line with 2014 (£249 million).

Bombed-out online flash sale retailer MySale (MYSL:AIM), backed by retail grandees Philip Green and Mike Ashley, rebounds 12.5% to 45p on a positive full-year trading statement. Following a poor first half, MySale's second half performance improved and management now expects a return to profitability at the earnings before interest, taxation, depreciation and amortisation (EBITDA) level in the coming year.

Consumer products powerhouse Reckitt Benckiser (RB.) rises 1.78% to £60.13 as strong first-half results including a better-than-expected margin performance, prompts the Cillit Bang-to-Air Wick producer to raise its 2015 guidance. Shares highlighted Reckitt's qualities in our recent 'Perfect Share' cover story.

China worries resurface as Shanghai's index of leading shares capitulate overnight, falling 345 points or 8.5% to 3,726. Investment trust Fidelity China Special Situations (FCCS) bears the brunt of the sell-off in the UK, falling 6.5% to 138p. JP Morgan Chinese Investment Trust (JMC), another China fund listed on the FTSE All-Share, sheds 4.2% to 166p.

Emerging markets-oriented funds not exposed to China also take a hit: Blackrock's Latin American Investment Trust (BRLA) is down 3.8% at 320p.

Credit bureau Experian (EXPN) is another stock being dragged in to the emerging markets sell-off. Slipping 2.8% to £11.52, the financial outsourcer, which does a large part of its business in Brazil, is the second-largest faller on the FTSE 100. It is also feeling the pain from a downgrade by analysts at investment bank Exane BNP Paribas, who reiterate a 'neutral' rating on the stock and downgrade their price target from £11.85 to £11.50.

Drug developer ImmuPharma (IMM:AIM) jumps 8.4% to 45p on being cleared to put its Lupuzor treatment for autoimmune disease Lupus into Phase III clinical trials. The company has secured a $14 million convertible loan to fund the tests.

Animal-focused biotech Benchmark (BMK:AIM) gains 4% to 64.5p on buying Norwegian aquaculture genetics and research business Akvaforsk and 80% of its US business for £11 million. The deal strengthens Benchmark’s operations by adding the tilapia, an African freshwater fish, to its breeding offering.

Laboratory services and products provider Source BioScience (SBS) is to add microbiology, chemistry and physical property testing to its expertise after agreeing to buy Select Pharma Laboratories for £7.3 million. Source climbed 7.1% to 15p on the news.

Low cost Irish carrier Ryanair (RYA) edges 0.9% higher to €12.16 after the group's first quarter results show the Dublin-based airline posting a 25% increase in profit after tax to €245 million on the back of a 16% increase in passenger numbers in the three months to the end of June.

Aerospace and engineering group Senior (SNR) is down 1.3% at 274p after the group posted interims which show pre-tax profit at the Rickmansworth-basd £1.1 billion cap slip slightly to £45 million on revenues £434.5 million in the six months to the end of June.

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Issue Date: 27 Jul 2015