UK stocks were expected to open lower on Tuesday as investors eyed geopolitical developments in Ukraine and awaited key economic data from Germany. City sources predict the FTSE 100 will open around 10 points lower than Monday's close of 6,632.82. The index advanced 1% on Monday on the back of improved newsflow from Iraq, Gaza and Ukraine. In particular, investors welcomed reports of Russia stopping military exercises near the eastern border of Ukraine over the weekend.Ukraine and Russia are now said to have agreed on a Red Cross-led humanitarian aid mission in Luhansk, where thousands of people are without access to water, power and medical help.However, with Ukrainian officials claiming that up to 45,000 Russian troops still remain close to the frontier, tensions between the neighbouring nations still remain high with developments having the potential to spark volatile moves on financial markets."While yesterday's gains were welcome the key question now being asked is whether yesterday's rebound is anything more than the proverbial dead cat bounce," said Michael Hewson, chief market analyst at CMC Markets UK.On the macro calender on Tuesday, traders will be keeping a close eye on the ZEW surveys in Germany which are expected to show that confidence has dipped this month. The headline economic sentiment index, which surveys financial experts, is forecast to fall to 17 from 27.1 in July.Stocks to watchHigh street bookie Ladbrokes said it delivered on its key operational objectives in the first six months of 2014, after a good World Cup performance pushed revenues higher. However, group profits fell sharply in the first half as a result of "industry-wide customer-friendly results, notably in football in January and horse racing in June", the company said.Troubled support services group Serco reported "poor" first half trading and predicted challenges ahead, but said it had reduced net debt and appointed a new finance chief.Hospital chain operator Al Noor Hospitals, Abu Dhabi's largest private healthcare provider, saw underlying profits before tax increase 33.6% to reach $45.6m on the back of a 25.2% increase in revenues to $224.8m. The company said it was "on track to deliver strong growth and achieve our objectives for 2014".Online takeaway marketplace Just Eat said earnings per share trebled in the first half of 2014 on the back of strong demand and an accelerating growth in mobile.BC