CSR Ltd (ASX:CSR) Australia's biggest sugar milling company, says the Overseas Investment Office (OIO) in New Zealand has given the greenlight for the sale of its sugar division to an overseas buyer.

Singapore firm Wilmar International can now continue with its proposed acquisition of Sucrogen for A$1.75 billion.

No further regulatory approvals are required for the transaction to proceed and CSR expects the sale to be completed on December 22, this year.

Earlier today, both CSR and Wilmar have agreed to extend the cut-off date in the share sale agreement to provide further assurance in the event of a further delay.

The cut-off date, allowing either party to terminate the agreement if conditions precedent to the sale have not been satisfied, has been extended from 31 December 2010 to 31 January 2011.

CSR said there are no other changes to the terms and conditions agreement.