The group – which earlier this year fought off an attempted takeover by US giant International Paper Co. (NYSE:IP) – said its operating profit before exceptional items for the six months to the end of June rose by 48% to €529mln (£471mln) as revenue increased by 5% to €4.4bn.
The Dublin-based firm said it benefited from lower recovered fibre costs which were €73mln in the first half. The cost of recovered fibre, used in the company's products, will rise in the longer term but the short-term outlook is uncertain, it added.
The company's chief executive, Tony Smurfit, commented: “As we start the second half, business conditions remain strong. We are excited about our prospects and we continue to expect our 2018 [earnings] to be materially better than 2017."
The group raised its interim dividend by 10% to 25.4 euro cents.
Smurfit Kappa received two takeover approaches by International Paper in 2018 but the US company withdrew its interest in May when it decided not to launch a hostile bid.
The UK blue-chip firm argued it had better growth prospects alone and declined to discuss International Paper's €8.9bn proposal.