Three prominent Russian businessmen subject to US sanctions have been informed that they will not be welcome at January’s annual World Economic Forum event in Davos, in a sign of the increased wariness among international organisations to deal with those blacklisted by Washington.

Aluminium magnate Oleg Deripaska, industrial tycoon Viktor Vekselberg and VTB Bank head Andrei Kostin have in effect been barred from the elite gathering in Switzerland, two people with knowledge of the decision told the Financial Times, despite there being no legal impediments to them attending.

The decision to bar the trio undermined efforts by the WEF’s organisers to convince Russian president Vladimir Putin to attend the event for the first time in a decade, one of the people said.