(ShareCast News) - London's mid-cap index was up 1.2% to 17,037.67 on Tuesday, tracking broader gains in the market as investors took comfort from a better-than-expected report on Chinese exports.Shares in Amlin surged after Japan's Mitsui Sumitomo Insurance Company said it has agreed to buy the UK insurer for £3.47bn. Under the terms of the deal, Mitsui will pay 670p a share for Amlin, whose shareholders will receive an 8.4p per share dividend to be paid on 1 October.RBC Capital Markets said the deal was highly attractive for Amlin and upgraded the stock to 'sector perform' from 'underperform' on the news. "The recommended cash offer for Amlin by Mitsui Sumitomo represents strong value for shareholders, in our view, at the highest takeout multiple seen in the sector in recent times," it said.Peers Lancashire Holdings, Beazley and Esure tracked Amlin higher on sector consolidation hopes.Ashmore Group was a high riser. The company posted a 21% drop in assets under management in the year to end of June, but profit and revenue increased and it said fundamentals across emerging markets remain sound. AUM fell to $58.9bn from $75bn last year, while pre-tax profit rose 6% to £181.3m and net revenue were up 8% at 283.3m.RBC Capital Markets said: "We believe the share price reaction is in part the result of a short squeeze on the headline profitability beat. However, we continue to believe that consensus will likely be subject to material downward revisions post results on the basis of mark-to-markets and incorporating the guidance given in the presentation."On the downside, Home Retail Group dropped after Morgan Stanley downgraded the stock and cut its price target, pointing to concerns about the impact of the new National Living Wage on long-term margins. "We believe the Living Wage announcement represents one of the biggest new structural challenges for UK retailers since the advent of the internet," the bank thundered.The new minimum wage, which Chancellor George Osborne introduced in his July budget, targeted to reach at least £9 per hour by 2020 above the current £6.50 per hour, has seen retailers generally downplay the issue but MS warned that it warrants closer attention from investors.Aldermore Group was also under pressure after research by accountants EY revealed on Monday that the banking sector, particularly 'challenger' banks like Aldermore, will have to pay out significantly more than expected from Chancellor George Osborne's new profits surcharge.RisersAmlin (AML) 655.00p +32.99%AO World (AO.) 149.70p +9.27%Ashmore Group (ASHM) 260.10p +6.25%Ocado Group (OCDO) 339.00p +5.38%Lancashire Holdings Limited (LRE) 688.00p +5.36%Serco Group (SRP) 110.00p +5.06%esure Group (ESUR) 244.20p +4.40%Aggreko (AGK) 1,081.00p +4.34%Beazley (BEZ) 342.00p +4.30%Evraz (EVR) 71.05p +3.95% FallersPetra Diamonds Ltd.(DI) (PDL) 114.70p -3.69%Lonmin (LMI) 24.47p -2.97%IP Group (IPO) 233.60p -2.05%Wetherspoon (J.D.) (JDW) 730.00p -2.01%Supergroup (SGP) 1,428.00p -1.65%Dunelm Group (DNLM) 897.50p -1.37%Domino's Pizza Group (DOM) 842.50p -1.23%Home Retail Group (HOME) 147.00p -1.21%Centamin (DI) (CEY) 59.30p -1.17%Aldermore Group (ALD) 292.00p -1.08%