Aug 2 (Reuters) - Australia's Incitec Pivot has sought out Indonesia's state-owned firm Pupuk Kaltim as a preferred buyer for its flagship fertiliser business, in a deal that could be worth about A$1.5 billion ($989 million), the Australian Financial Review reported on Wednesday, citing sources familiar with the matter. ($1 = 1.5165 Australian dollars) (Reporting by Archishma Iyer in Bengaluru; Editing by Dhanya Ann Thoppil)