AngloGold Ashanti, the world's third-largest gold producer, said on Tuesday it expects capital expenditure to double to $1.5 billion dollars by 2013.

The company said in a presentation on its website that it then saw capex falling back to 2011 levels by 2015 as some of its projects come on stream.

Long-term and large capex outlays will include an estimated $3.4 billion for the company's massive La Colosa project in Colombia, which authorities have said could threaten farming and human populations because of the water resources required.

The presentation forecast that project would not reach full production before late 2019 with production seen rising to as much as 900,000 ounces a year once it gets going.

For the Americas region the group said it is targeting average annual production of between 1.2 and 1.9 million ounces a year by 2020, a wide range.

The company also said it would continue looking for opportunities to expand the Americas portfolio.

For the group's continental African operations, which include Mali, Ghana and Tanzania, it saw output rising significantly to 2 to 2.3 million ounces per year by 2014/15 with new projects in the Democratic Republic of Congo slated to come into production.

The group's Mongbwalu project there should start delivering its first gold in 2013 and the capex to develop the mine is estimated to be around $400 million, the presentation said.

On its balance sheet the group said it had reduced net debt from $2.4 billion to around $600 million currently while net cash flow is seen rising to around $750 million this year from just over $500 million last year.

Cash flow has been freed up since the group eliminated its hedge-book, which involved gold sold forward or covered by derivatives.

This at times had previously curbed cash flow but the company is now full exposed to the gold price which scaled historic peaks in September.

It also said it could support net debt levels of $1.8 to $2 billion.