Smurfit Kappa improved underlying profits in spite of rising input costs, but the chief executive of Europe’s largest cardboard box manufacturer conceded it faced an uncertain year.

In its first set of full-year results since floating last March, the Irish packaging maker – whose customers include some of the world’s largest consumer-facing companies such as Unilever, Procter & Gamble and Coca-Cola – said it had increased prices to reflect higher raw materials and costs.