Rio Tinto announced that it plans to cut its capital spending in half to $8 billion by 2015 to cut debt amid falling commodity prices.

The cuts are sharper than some investors had expected and deeper than those made by Rio Tinto's major rivals, Reuters reported.

The cuts show that the company is focused on boosting shareholder returns and protecting its credit rating.

Rio Tinto announced earlier that it would delay the expansion of its iron ore operations in Australia to 2017 but save $3 billion in the process. The company is also in the midst of selling a clutch of coal, copper and other non-core assets.

The company plans to cut capital spending to $11 billion in 2014 from just under $14 billion this year, and sees capital spending at $8 billion in 2015, which would be less than half what it was in 2012.

The cuts are more than that of its bigger iron ore rival Vale of Brazil, which unveiled a 9 percent capital spending reduction to $14.8 billion for 2014.

Rio Tinto executives told an investor seminar in Sydney the firm has stripped out $2.6 billion in costs so far this year, including nearly halving exploration spending to around $850 million.

Rio Tinto aims to cut net debt to the "mid-teens" next year from $22 billion, as reported at the half year in 2013, Rio Tinto Chief Financial Officer Chris Lynch said.

Prices of iron ore , which made up more than 80 percent to Rio Tinto's first-half earnings, have rallied since hitting mid-year lows but they are still down around 14 percent from 2013 highs and off nearly 30 percent compared to all-time highs hit in early 2011.