Company corporate affairs manager, Eugene Chungu, said in an interview in Lusaka that the increase has been necessitated by the continued devaluation of the Kwacha.
Mr Chungu said the price of input material such as coal, which is sourced from Zimbabwe, has gone up.
“Since last September, the Kwacha has just been depreciating from around K3,300 to K5,700 and, as a company, we did not effect the price change there and then,” he said.
Mr Chungu dispelled assertions that that increase was a result of the closure of one plant.
He said the plant had been closed for environment reasons.
