Origin Energy has allocated $800 million of subordinated notes, the proceeds of which will be used to fund the company’s share of the Australia Pacific LNG project, and other general purposes.

The initial offer size had been $500 million but Origin increased the allocation after strong support by institutions and brokers.

The final size of the offer would depend on the volume of applications received under a shareholder offer and general offer, Sydney-based Origin said in a statement on Thursday.

The company said it had set the margin at 4.00 per cent and the notes would mature on December 22, 2071.

Based on the current bank bill rate, the initial interest rate will be about 8.6 per cent.