Tetra Laval, the Swedish packaging group, is preparing to appeal against the European Commission's impending veto of its €1.7bn ($1.5bn) takeover of Sidel, its French counterpart, which was completed earlier this year.

Sources close to the two companies said the European Commission is set to block Tetra's ownership of Sidel on Tuesday, just one week after the directorate's merger task force gave a negative preliminary ruling against the deal. It is rare for the Commission to alter from a preliminary ruling.