The group, which provides distribution solutions for the chemical, polymer, food and mineral industries, said it has seen an "encouraging" recovery in second-half turnover and operating profit. But it conceded continuing difficulties in the European polymer market, which has a direct effect on its dry bulk business, would lead to lower than forecast profits for the year ended September 30.
Interbulk finance director Scott Cunningham said: "A key message is that we have seen improvement both in the revenue and in the operating profit in the second half of the year, which is encouraging.
"But it was not quite at the pace we had hoped for, especially in the dry bulk business, which is mainly focused on Europe. We continue to see uncertainty in Europe, certainly with our customer base. As a result, some of the expectation was lower in that area of the business."
The company's dry bulk division distributes containers of 24 tonnes of plastic pellets from the chemical industry for use in plastic packaging, bottles and construction. Mr Cunningham said it has been challenged as customers behave more cautiously, focus on costs and plan less for the long term.
He said: "We can be busy one week and quiet the next. It is the volatility that is more of an issue for us, and also the production of chemicals in Europe is a negative number this year in 2013.
"Obviously that backdrop reflects the slower economic position in Europe from where everybody thought it might be."
However, he said the outlook was brighter for its more global liquid bulk operation, in spite of pressure on margins because of increased competition.
Mr Cunningham, who said the firm employs 200 of its 500 staff in the UK, added: "These days most of our business is about moving product between continents and outside Europe is certainly more robust and has seen a decent second half, which keeps us in line with where we hoped it would be by the year end.
"The liquid bulk is the bigger side in terms of revenue and profit for us. That has grown over the years because of this activity outside Europe we do. In dry bulk we are trying to replicate that. The dry bulk business has opportunities outside Europe as well and that is where he are trying to use the network we have in the world for liquid bulk and introduce the dry bulk concept to the customer base."
Kevin Fogarty at house broker Westhouse Securities lowered its expectation for full-year EBITDA (earnings before interest, taxation, depreciation and amortisation) to £16.3 million from £17.8m, and cut its profit before tax forecast to £2.6m from £4m.
Shares in Interbulk closed down 0.75p at 6.62p.