BHP Billiton said it has approved $9.5 billion of capital investments to expand Australian iron ore and coal mining projects, in the first details the global miner has given of a planned $80 billion in investments over five years.

The world's biggest miner has decided to expand its own operations and infrastructure rather than chase ambitious takeovers, after three failed takeover bids, as it scrambles to meet rising demand from Asia.

The top global miner said it would invest $6.6 billion in a total investment of $7.4 billion to continue production growth in the company's western Australian iron ore operations.

Investment will include the development of the Jimblebar mine, rail links and additional berths and ship loaders at its Port Hedland site.
BHP said it had also approved three key metallurgical coal projects at its Bowen Basin site in Queensland.

BHP will put in $2.5 billion of the total $5 billion investment, which will see the new Daunia mine developed, its Broadmeadow mine's life extended by 21 years and the stage three expansion of its Hay Point coal terminal.

In a third statement, the company said it had approved a $400 million investment to expand Hunter Valley Energy Coal in New South Wales with a view to increasing production.

The three announcements are the first in the company's planned $80 billion expansion plans announced last month, as it posted a near doubling of first-half profits to $10.7 billion.

BHP has ditched three major deals in the past three years, including its $39 billion bid for top global fertilizer maker Potash Corp last year, mainly on regulatory concerns.