Australia's Fortescue says pays off more debt early

SYDNEY, Aug 20 (Reuters) - Australia's Fortescue Metals Group said on Wednesday it has made further headway in paying down some $12 billion in debt it amassed building the world's fourth-biggest iron ore mining company over the past decade.

Fortescue said it plans to redeem $500 million of senior unsecured notes in October. It did not give a figure for net debt, but said earlier this month that net debt stood then at $7.2 billion after it repayed $3.1 billion in fiscal 2014.

The company said it intends to repay an additional $500 million to $1 billion during fiscal 2015, subject to iron ore prices and other market factors.

Australia's No. 3 iron ore miner, Fortescue is one of a small number of mega miners flooding the sea-traded market with cheaply produced iron ore in a bid to knock out competitors.

The miner is maintaining production above its target rates as it vies to capture more of China's 1 billion-tonne-per-year market for the steel-making ingredient.

(Reporting by James Regan; Editing by Richard Pullin)