Sept 18 (Reuters) - Investa Office Fund IOF.AX :
* BLACKSTONE RETAINS ABILITY TO NOT WAIVE REQUIREMENT FOR SEPT 17 MEETING, IN WHICH CASE PRICE UNDER PROPOSAL WILL BE $5.3485
* BLACKSTONE RETAINS ABILITY TO ELECT TO RAISE OFFER ABOVE $5.3485 OR $5.52 GIVEN EXISTENCE OF CONDITIONAL COMPETING PROPOSAL
* BLACKSTONE RETAINS ABILITY TO WAIVE REQUIREMENT FOR SEPT 17 MEETING WITH OFFER PRICE AT $5.52 PER IOF UNIT
* UPDATE ON BLACKSTONE'S POSITION