Stocks across Europe are expected to be fall on Friday morning as investors scale back their appetite for risk amid increased geopolitical tensions in eastern Europe following the downing of a commercial aircraft. City sources predict the FTSE 100 in London will open around 13 points lower than Thursday's close of 6,728.32.A Malaysian airliner with 295 people on board crashed near Ukraine's border with Russia yesterday afternoon, allegedly after being shot down by pro-Russian rebels. The Malaysian Airlines jet is said to have come down near Shakhtersk, some 25 miles from border, where Ukrainian troops and pro-Russian rebels have been fighting.A Ukrainian interior ministry official blamed militants for the crash near Ukraine's border with Russia, claiming they shot down the Boeing 777 using a ground-to-air missile. However, rebel leaders have said that Ukrainian forces shot the airliner down, a claim which Kiev denied."Until further clarification on the cause of the crash can be obtained then markets are expected to open today's session lower. Unless somebody/group takes credit, it could take a number of days to determine who's to blame and until then markets could be faced with risk-off sentiment," said Jasper Lawler, Market Analyst at CMC Markets UK.Stocks to watchAirline stocks will likely be under heavy selling pressure this morning as investors continue to digest the latest developments in Ukraine.A spokeswoman for British Airways, owned by IAG, said BA aircraft were not using Ukrainian airspace with the exception of the airline's daily flight between London and Kiev, which is not near the crash site. She said the airline was keeping services under review.DCC, the sales, marketing, distribution and business support services group, said that trading for the first quarter was in line with expectations as the company raised its guidance slightly for the full year. The firm expected operating profit and adjusted earnings per share to rise 10-12% in the financial year ending March 2015, compared with previous guidance for 10% growth.Home repairs and insurance group Homeserve reported good UK trading and said it was on track to match hopes, although trading would be weighted towards the second half of the financial yearBuilding product distributor SIG has bought French rival Sodimat for €4.4m in cash. SIG is buying Lyon-based Sodimat, which distributes flat roofing products in France, from the Sitbon family, which founded the business.BC