The European Union extended its sanctions on Russia and rebels in eastern Ukraine on Friday, adding 15 companies and 24 individuals to its blacklist and imposing new measures against the country’s oil and defense sectors, in an effort to target those dealing with the separatists. The measures, initially approved on Monday, reinforced steps taken in July restricting trade, commerce and financial links with Russia. They will indirectly affect companies including Exxon Mobil Corp., which works with state-controlled oil companies in Russia. Under the widened sanctions list, it is “prohibited to directly or indirectly purchase, sell, provide investment services for or assistance in the issuance of, or otherwise deal with transferable securities and money-market instruments with a maturity exceeding 30 days.” As previously reported in The Wall Street Journal, three state-controlled oil companies–OAO Gazpromneft, the oil unit of OAO Gazprom; oil pipeline operator company […]