London open: FTSE 100 retreats as Barclays and Aberdeen fall

- Barclays, Aberdeen and Balfour Beatty provide a drag- Ukraine tensions cap risk appetite- FTSE 100 pulls back from two-month hightechMARK 2,800.50 +0.22%FTSE 100 6,810.43 -0.18%FTSE 250 15,950.66 +0.12%UK markets opened slightly lower on Tuesday morning as traders adopted a cautious approach after stocks hit a two-month high the previous session.Barclays was among the worst performers after reporting a fall in first-quarter profits, Aberdeen dropped as seeing assets shrink in its first half, while Balfour Beatty saw shares plummet after a profit warning.The FTSE 100, which was closed on Monday for a public holiday, was down 0.2% at 6,810 in early trading today after having closed at 6,822.42 on Friday, its highest finish since March 4th.Heightened tensions in Ukraine were also keeping risk appetite in check today after an army helicopters was shot down yesterday by pro-Russian activists near the city of Sloviansk. Deaths have been reported on both sides amid heavy fighting along the eastern border as Kiev continues its so-called 'anti-terrorist' operations.Jonathan Sudaria, a dealer at Capital Spreads said that markets are "struggling for direction at the moment". "The situation in Ukraine looks set to be something that will continue to influence financial markets for a considerable amount of time, and markets will struggle to push much higher until investors can see a real improvement in the situation over in Eastern Europe," he said.Barclays, Aberdeen, Balfour BeattyBarclays was a heavy faller, blaming a weak performance in its investment banking arm for a 5% decline in quarterly adjusted pre-tax profit to £1.7bn in the first quarter, although it said its retail and credit card operations did well.Banking peers Lloyds and RBS, which both beat market forecasts last week with their quarterly results, were also trading in the red this morning.Aberdeen Asset Management was lower after suffering net outflows of £8.8bn in a "demanding" six months to end-March. Assets under management fell 5% to £190.4bn.Meanwhile, infrastructure services group Balfour Beatty sank sharply after saying "significant operational issues" meant pre-tax profits in 2014 were likely to come in between £145m-£160m, significantly lower than it forecast in March. It also said Chief Executive Andrew McNaughton had quit and would be replaced temporarily by Chairman Steve Marshall.Housing stocks were among the best performers of the morning with Persimmon, Barratt Developments, Travis Perkins and Bellway all making gains.Estate agent chain Countrywide rose after saying momentum in the later stages of 2013 continued into the first quarter of this year as the recovery in the residential property market continues.FTSE 100 - RisersPersimmon (PSN) 1,379.00p +3.92%Melrose Industries (MRO) 292.00p +2.28%Morrison (Wm) Supermarkets (MRW) 199.00p +1.43%Aviva (AV.) 530.50p +1.43%Vodafone Group (VOD) 226.00p +1.39%Pearson (PSON) 1,109.00p +1.37%Babcock International Group (BAB) 1,224.00p +1.32%Johnson Matthey (JMAT) 3,351.00p +1.30%CRH (CRH) 1,747.00p +1.22%United Utilities Group (UU.) 803.00p +1.13%FTSE 100 - FallersAberdeen Asset Management (ADN) 426.10p -4.44%Barclays (BARC) 248.40p -3.91%Anglo American (AAL) 1,535.00p -1.92%Coca-Cola HBC AG (CDI) (CCH) 1,452.00p -1.89%AstraZeneca (AZN) 4,721.50p -1.80%Rio Tinto (RIO) 3,190.50p -1.74%BHP Billiton (BLT) 1,900.50p -1.58%Fresnillo (FRES) 819.00p -1.56%Centrica (CNA) 323.80p -1.52%Glencore Xstrata (GLEN) 316.05p -1.00%FTSE 250 - RisersRentokil Initial (RTO) 126.50p +4.29%Perform Group (PER) 227.10p +4.17%Pace (PIC) 349.90p +3.83%Countrywide (CWD) 608.00p +3.05%Grafton Group Units (GFTU) 610.00p +2.87%ITE Group (ITE) 230.40p +2.49%Howden Joinery Group (HWDN) 345.80p +2.31%AL Noor Hospitals Group (ANH) 1,021.00p +2.10%Supergroup (SGP) 1,435.00p +1.99%Go-Ahead Group (GOG) 2,035.00p +1.85%FTSE 250 - FallersBalfour Beatty (BBY) 231.10p -19.14%Polymetal International (POLY) 547.00p -2.67%Croda International (CRDA) 2,510.00p -2.14%Carillion (CLLN) 366.50p -2.01%African Barrick Gold (ABG) 236.50p -1.87%Brown (N.) Group (BWNG) 457.20p -1.68%Lonmin (LMI) 288.00p -1.57%Dunelm Group (DNLM) 936.00p -1.47%St. Modwen Properties (SMP) 358.90p -1.46%Kazakhmys (KAZ) 242.40p -1.46%BC