The deal is expected to conclude in six weeks, subject to regulatory approval.

Sicpa's 2,800 staff would remain in plants in Finland, Belgium, Switzerland and France and become part of Siegwerk, which has 1,300 staff and a headquarters near Cologne, Germany.

Corporate spokesman Peter Heimirzheim said it was too early to say if there would be job losses or what the new set-up would be called. Joint turnover will be 520m.

"We need to integrate the businesses and envisage no expansion for maybe two years," he said. "This deal is not a big risk. We have a very good financial position and think packaging inks is an emerging business."

Sicpa's security inks division employing 700 staff is not affected by the deal.