New York-based buyout fund Kohlberg Kravis Roberts has walked away from plans to purchase the $2 billion telecommunications tower portfolio currently up for sale by Optus.

This leaves the remaining two members of its consortium, Ontario Teachers’ Pension Plan and the Queensland Investment Corporation, to battle it out at auction against other bidders, which includes a consortium including AustralianSuper – and the Crown Castle telco towers business Axicom.

Final bids for the towers are due in the latter half of September.

As part of the deal, Optus requires that whoever buys the towers has to own the majority of its Australian tower portfolio, and commit to building further towers. The portfolio contains 2000-2500 telco towers, and buyers are being offered around 70 per cent of the towers.

That 70 per cent generates an annual average of $100m before interest, tax, and depreciation.