The Portuguese company has said it has been forced to make the move, which will come into effect in September, because “the strong pressure on the industry's cost structure, continuous profitability deterioration and high operating rate has made the current prices unsustainable”.

Portucel is the latest in a series of paper manufacturers to raise prices.

In May, Sappi Europe announced an 8% price rise on its coated fine and coated mechanical paper reels from 1 July, citing low prices, tight margins and the high cost of wood pulp. It followed with a similar rise of 8% for its woodfree coated sheets and its woodfree uncoated sheets and reels by 5%-8% a few weeks later.

In the same month, Lecta also announced a 6%-8% price rise on its coated woodfree papers , also effective from the beginning of July. The group had already put the prices of its speciality papers up by 5%-7% in April.

And in June Mitsubishi HiTec Paper announced a rise for all the products in its range.

All three companies cited high production costs as the reason for the rise.