UK stocks are set to open slightly lower on Thursday as investors adopt a cautious stance ahead of the four-day weekend amid ongoing turmoil in Ukraine."The European open looks set to be a mixed affair as global indices seem undecided as to whether they are actually ready to start moving back towards highs seen back in February or else continue to correct lower which has been a running theme of the past fortnight," said Research Analyst Joshua Mahony from Alpari UK.City sources predict the FTSE 100 will open around seven points lower than yesterday's close of 6,584.17.Talks in Geneva between the US, Russia and Ukraine and the EU will be high on the agenda for global financial markets on Thursday, but the potential for more aggressive sanctions on Moscow may be limited given warnings from blue chip firms that they could affect business.Companies such as German chemical group BASF, Italian energy firm Eni and British oil major BP have expressed their caution to governments about the fall-out from tougher sanctions and any possible retaliation from the Kremlin. Turmoil along the eastern border of Ukraine has escalated in recent days due to the occupation of government buildings by pro-Russian militants.US stocks closed higher for the third day in a row on Wednesday as positive data from the Federal Reserve's 'Beige Book', which showed receding winter snow had revealed buds of economic activity in 10 out of its 12 regions across the country. Crowd-pleasing earnings from stocks such as Yahoo! and Intel also helped to lift sentiment, however, Google tumbled in after-hours trading as first-quarter revenue and earnings fell short of analyst expectations, with paid clicks also declining from the last quarter of 2013.Economic data is likely to be on the light side today, with few major indicators due for release. Initial jobless claims and the Philadelphia Fed manufacturing index will be in focus later on for US markets.Stocks to watchRoyal Dutch Shell has made an exploration discovery offshore Malaysia, the oil and gas giant announced on Thursday. The Rosmari-1 well, located 135km offshore in Block SK318, encountered more than 450 metres of gas column after being drilled to a total depth of 2,123 metres.Year-to-date organic revenue growth at beverages group Diageo has been held back by sales declines in the third quarter due to weakness across many emerging markets. The company, famous for spirits brands Johnnie Walker, Captain Morgan and Smirnoff as well as Guinness stout, said that organic net sales fell by 1.3% in the three months to March 31st. As a result, overall growth over the first nine months of Diageo's financial year was just 0.3%, down from 2% in the first half.Residential development group Taylor Wimpey said the UK housing market remains buoyant as demand continues to be buoyed by the more accessible and affordable mortgage market. It made a particularly strong start to the year and is confident that its strategy will deliver at least 200 to 300 basis points of operating margin improvement in 2014, and further improvement in 2015 and beyond, it said.RSA Insurance Group has sold off its Baltics and Polish businesses as Chief Executive Stephen Hester, the former RBS boss appointed in February, attempts to turn around the embattled insurer. The FTSE 100 group has reached agreement in four transactions, which if they complete will reap a total cash consideration of approximately €360m (£300m).BC