Royal Bank of Scotland's shares edged up after narrowing its shortlist of prospective bidders in its sale of 315 branches.UK gas and electricity supplier Centrica advanced Friday as utility stocks bounced back after a sharp fall over the past week. Polymetal International rallied after completing the acquisition of the Svetlobor platinum exploration project.Old Mutual, WPP and Standard Life fell as the FTSE 100 edged lower following a week of volatility in UK equities.Building materials company, CRH retreated after analysts downgraded its ratings on its stocks. Credit Suisse issued a 'underperform' rating while Goodbody Stockbrokers recommended a 'sell'.FTSE 100 - RisersRoyal Bank of Scotland Group (RBS) 337.80p +1.90%Centrica (CNA) 382.90p +1.84%Polymetal International (POLY) 697.00p +1.01%Randgold Resources Ltd. (RRS) 5,275.00p +0.96%Fresnillo (FRES) 1,167.00p +0.95%Lloyds Banking Group (LLOY) 62.32p +0.84%Severn Trent (SVT) 2,065.00p +0.78%BG Group (BG.) 1,224.00p +0.74%Weir Group (WEIR) 2,346.00p +0.73%BT Group (BT.A) 305.50p +0.69%FTSE 100 - FallersOld Mutual (OML) 203.40p -3.28%WPP (WPP) 1,135.00p -2.58%Standard Life (SL.) 393.40p -2.45%CRH (CRH) 1,400.00p -2.44%Experian (EXPN) 1,233.00p -2.38%Evraz (EVR) 139.00p -2.32%Prudential (PRU) 1,127.00p -2.17%IMI (IMI) 1,299.00p -2.11%Tate & Lyle (TATE) 820.50p -1.91%Vedanta Resources (VED) 1,282.00p -1.84%RD