Shares in Cable & Wireless Worldwide (CWW) plunged following the revelation that Tata Communications has decided not to bid for the firm. This news leaves Vodafone as the only shark circling the ship, but it only has until 17:00 today before the bid deadline runs out. CWW said late last night that discussions with the FTSE 100 group are still ongoing, but "there can be no certainty that any offer will be made, nor as to the terms of any offer."Mining group Talvivaara dropped after reiterating that full-year nickel production will be at the lower end of its guidance and saying that it has made an operating loss for the first quarter.High Street betting shop Ladbrokes rose strongly after net revenue in the first three months of 2012 improved by 8.9%. FTSE 250 - RisersRenishaw (RSW) 1,448.00p +7.42%Exillon Energy (EXI) 141.30p +6.08%Kenmare Resources (KMR) 54.00p +5.68%Ladbrokes (LAD) 170.60p +4.79%Dixons Retail (DXNS) 17.84p +4.33%Spirit Pub Company (SPRT) 55.75p +4.21%Ashtead Group (AHT) 260.60p +3.25%Rotork (ROR) 2,228.00p +3.01%Fenner (FENR) 453.60p +2.72%William Hill (WMH) 265.40p +2.63%FTSE 250 - FallersCable & Wireless Worldwide (CW.) 30.86p -16.71%Talvivaara Mining Company (TALV) 192.70p -14.36%Home Retail Group (HOME) 98.75p -4.96%African Barrick Gold (ABG) 351.70p -4.66%Kier Group (KIE) 1,133.00p -3.90%Essar Energy (ESSR) 140.20p -3.77%Computacenter (CCC) 415.70p -3.68%Kesa Electricals (KESA) 55.20p -3.41%WH Smith (SMWH) 529.50p -3.20%Soco International (SIA) 290.40p -2.84%NR