The chief executive officer of Canadian gold producer Iamgold Corp. canceled a trip to a Russian economic forum hosted by President Vladimir Putin amid the threat of tougher U.S. sanctions over the unrest in Ukraine.

Political “sensitivities” played a role in CEO Steve Letwin’s decision not to attend the event next month, according to Bob Tait, a spokesman for the Toronto-based company. Tait spoke in a telephone interview today.

Citigroup Inc. said yesterday that its CEO, Michael Corbat, withdrew from the St. Petersburg International Economic Forum and that other bank executives would go in his place.