Unipetrol AS (UNIP), the biggest Czech oil refiner, declined after E15 newspaper reported that Industry and Trade Minister Martin Kuba proposed a new tax on motor fuels.

The stock slipped 1.7 percent, the most since April 6, to 170.11 koruna by 11:29 a.m. in Prague. The 14-member PX (PX) index, where Unipetrol has a 4.2 percent weighting, slid 0.6 percent.

To contact the reporter on this story: Krystof Chamonikolas in Prague at kchamonikola@bloomberg.net

To contact the editor responsible for this story: Gavin Serkin at gserkin@bloomberg.net