The UK is letting the side down for private equity investor 3i, today's biggest faller among Footsie constituents."Overall, the private equity portfolio has performed well," chief executive Michael Queen said. "There have, however, been marked regional differences, with strong growth in Northern Europe counterbalanced by weaker performance from UK companies."UK banking shares were in demand throughout the day, enjoying a halo effect after the publication late yesterday of the Irish banks stress tests. Irish banks need another €24bn (£21bn) to secure themselves against any deterioration in the economy, the governor of the ailing country's central bank Patrick Honohan said.FTSE 100 - RisersJohn Wood Group (WG.) 670.00p +5.10%Lloyds Banking Group (LLOY) 61.00p +5.01%Randgold Resources Ltd. (RRS) 5,200.00p +4.67%Barclays (BARC) 289.45p +4.29%Inmarsat (ISAT) 627.00p +3.81%Royal Bank of Scotland Group (RBS) 42.34p +3.80%Admiral Group (ADM) 1,611.00p +3.67%BP (BP.) 470.00p +3.52%Prudential (PRU) 730.50p +3.40%Pearson (PSON) 1,138.00p +3.36%FTSE 100 - Fallers3i Group (III) 285.80p -4.38%Serco Group (SRP) 548.00p -1.79%InterContinental Hotels Group (IHG) 1,264.00p -1.10%International Power (IPR) 305.20p -0.91%Capita Group (CPI) 739.50p -0.47%Hargreaves Lansdown (HL.) 608.00p -0.33%Sainsbury (J) (SBRY) 334.40p -0.27%TUI Travel (TT.) 226.40p -0.26%International Consolidated Airlines Group SA (IAG) 226.70p -0.13%Amec (AMEC) 1,192.00p -0.08%