LONDON (BLOOMBERG) - Glencore, the world's biggest commodity trader, has offered to buy back as much as US$1.25 billion(S$1.70 billion) of its bonds as part of a plan to reduce debt.

The company offered to buy notes due in 2018 and 2019, according to a statement on Monday. The cash offer will expire on Oct 31 and there's an early tender deadline of Oct 17. Last week, Rio Tinto Group, the second-largest mining company, offered to repurchase as much as US$3 billion of its bonds.

The world's biggest miners are paying down debt to help combat a downturn in prices that has forced them to slash dividends, rein in spending and sell assets. Glencore's chief executive officer Ivan Glasenberg enacted a broad debt reduction plan last year to combat heightened investor concern around its US$30 billion debt load.

The company aims to reduce debt to as low as US$16.5 billion by the end of the year after selling assets, including 49 per cent of its agriculture business for about US$3.1 billion.

S&P Global Ratings raised its outlook on Glencore to positive from stable last week, citing progress on asset sales and higher prices for key commodities. The shares rallied 138 per cent this year as commodity prices rebounded and investors gained confidence in the company's ability to ride out the downturn.

Mr Peter Grauer, the chairman of Bloomberg LP, is a senior independent non-executive director at Glencore.