A sharp fall for Yukos shares weighed on the Moscow market yesterday after the oil group warned that a Dollars 3.4bn tax bill could damage its production forecasts for the year. Simon Kukes, Yukos's chief executive, said a failure to overturn the tax demand at the next hearing on June 18 would force the company to sharply lower investments and miss a 10 per cent output growth target for this year. Yukos shares fell 6.4 per cent to Dollars 7.58 while the Russian RTS1 index shed 3.1 per cent to 571.67. Yukos had already warned that it could go bankrupt by the end of the year if it were forced to pay the Dollars 3.4bn demand, which relates to the 2000 financial year. Analysts have also suggested that tax demands for other years could push the bill as high as Dollars 10bn. Turkish stocks edged ahead as investors waited for news from the International Monetary Fund's latest review of the country's Dollars 19bn loan accord. Ankara has made it clear that it would like to sign another pact after this one expires next year. The ISE-100 index rose 1 per cent to 17,786.42. Sentiment was helped by a decision to release four lawmakers, who were seen as prisoners of conscience by the European Union. The move may help Turkey secure a date to begin talks on joining the EU.