The Green Pasture Software company, who specialise in content management software, have been bought by IBM, IBM has said. Details of the deal were not announced.

This was the 13th purchase since 2001 for IBM's software division. It is estimated that the content management software market will increase to over $US9 billion by 2007.

The software from Green Pasture concentrates on complex documents, allowing customers to electronically collaborate, edit and manage documents simultaneously.