Takeover target Afren was weaker as the deadline for suitor Seplat to return to the table with a possible offer was extended. The Nigerian group approached its FTSE 250 peer last month about a potential tie-up and has until 17:00 on Friday 30 January to 'put up or shut up', according to takeover rules.Fidelity China Special Situations fell as Chinese stocks were hit by a clampdown on the country's three largest stockbrokers from opening new margin trading accounts for three months. China's stock market fell 7.7% on the news, its biggest drop since 2009.Also falling was Soco International, after the company had its price target cut from £3.35 to £2.85 by JPMorgan in a note to clients on Monday.Meanwhile, Premier Oil shares were boosted by a favourable Credit Suisse report, which hailed management's achievement of 10% cost cut across both operating costs and corporate overhead.Oil services stocks were also up despite falling oil prices, including Hunting and Wood Group.Risersesure Group (ESUR) 236.40p +6.01%Premier Oil (PMO) 146.30p +4.05%Hays (HAS) 149.50p +3.46%Centamin (DI) (CEY) 70.85p +3.43%NMC Health (NMC) 484.00p +2.98%Hunting (HTG) 457.20p +2.95%Playtech (PTEC) 669.50p +2.92%Lonmin (LMI) 177.10p +2.91%Worldwide Healthcare Trust (WWH) 1,815.00p +2.89%Wetherspoon (J.D.) (JDW) 823.00p +2.88%FallersAfren (AFR) 26.85p -9.60%Card Factory (CARD) 267.80p -4.19%Fidelity China Special Situations (FCSS) 134.60p -4.13%Vedanta Resources (VED) 389.90p -3.82%Soco International (SIA) 255.50p -2.14%Jimmy Choo (CHOO) 169.20p -1.97%Capital & Counties Properties (CAPC) 367.10p -1.53%COLT Group SA (COLT) 128.20p -1.31%Grainger (GRI) 185.80p -1.22%Derwent London (DLN) 3,128.00p -1.17%