It had already turned off two machines and made 134 employees redundant, but the passing of the deadline to find a buyer means all 550 employees will now be made redundant and the plant will be closed completely by the end of August.
Chief executive Barry Wiersum said: "The process to find a suitable purchaser included numerous discussions with interested parties and involved close cooperation between local mill management and Sappi’s European and global management teams to make the purchase as attractive as possible
"Unfortunately several industry players quickly withdrew their interest and we were unable to come to an agreement with any other interested parties."
The move reduces Sappi's graphic paper capacity by 500,000 tonnes per annum.