A Czech central banker said Tuesday more intervention to weaken the country's currency against the euro may be needed amid slow growth in Europe. His remarks sent the koruna to its weakest level in 4½ years.

Lubomir Lizal said it is conceivable that the country's central bank may intervene on foreign exchange markets to bring the koruna down to a rate of 28 to the euro from 27.33 koruna late Tuesday.