Shares in Africa Israel Investments Ltd., one of Israel's largest companies, have plummeted by one-third in two days after billionaire diamond baron Lev Leviev acknowledged possible problems paying off billion of dollars in company debts. The holding and investment company, in which Leviev owns a 75 percent stake, has lost some $1.4 billion since the beginning of 2008, battered in large part by soured real-estate investments in the US and Russia. On Monday, the company's shares on the Tel Aviv Stock Exchange shed 13.6 percent, having lost 25% a day earlier over Africa Israel's announcement it might have trouble making debt payments by 2011 and was seeking to restructure its obligations. The company's debt currently totals some $5.5b., at a time when declining global property prices have forced Africa Israel to sharply write down the value of its assets. Africa Israel is one of the country's largest companies, but its troubles aren't reflected as sharply in the broader economy, which is less heavily exposed to the global real-estate crisis. Last week, the Moody's credit ratings service said Israel's economy has largely weathered the global meltdown and the Africa Israel's real-estate portfolio in the US includes the former New York Times building, other Manhattan properties and real estate in Miami, Los Angeles and Phoenix. The company also owns property in Germany, Hungary, the Czech Republic, Serbia, Romania and Bulgaria. The Uzbek-born Leviev also owns one of the world's largest diamond-cutting and -polishing businesses, as well as mines in Africa and Russia. A major competitor to the De Beers diamond cartel, the self-made Leviev ranked 468 on Forbes's latest list of the world's richest people, with a reported net worth of $1.5b. His considerable wealth and support for Jewish educational and philanthropic causes have given him access to Israeli leaders and to Russian Prime Minister Vladimir Putin. But his construction activities in Judea and Samaria have come under fire from settlement opponents in the US and Britain. UNICEF, the UN children's agency, stopped accepting contributions from Leviev because of an Africa Israel subsidiary's business in the West Bank.