DS Smith said trading in the first half of the year was is in line with its expectations, with return on sales broadly consistent with that reported for the full year to 30 April 2017.
Return on average capital employed, meanwhile, was at the upper end of the target range, the packaging company said.
The integration of recently-acquired Interstate Resources was proceeding "very well", it added.
"We are pleased with the consistently strong organic progress of the business," chief executive Miles Roberts said.
"Customers continue to demand high-quality, innovative packaging on a multi-national basis and we have the scale and expertise to serve them."
"We have also strengthened our business model further through selective acquisitions, in Europe and US, driven by customer demand. As such, we view the future with confidence."