The world's biggest miner, BHP Billiton, said Wednesday the planned blockbuster merger between Glencore and Xstrata would not impact on its strategy.

Commodities titan Glencore and mining firm Xstrata announced a vast merger on Tuesday, creating a US$90 billion group and heralding a new powerhouse in the industry.

The new company would combine Glencore's global trading network for energy, metals and farming products with Xstrata's mines, posing a challenge to Melbourne-based BHP and fellow major Rio Tinto.

But BHP chief Marius Kloppers said he did not expect a major impact on his company's focus.

"I would say it doesn't make a difference to our strategy, it doesn't make a difference to our philosophy," he said following the release of half-year profit results, which fell 5.5 percent to US$9.94 billion.

BHP will continue to invest heavily in large, long-life, low-cost assets that can be expanded, Kloppers added.

"We believe the potential of a resource company will be defined by its resource base," he said.

Glencore is offering 2.8 of its shares for each Xstrata share held.

The new company is expected to increase production by 11 percent annually to 2015 and have a significant presence in African copper mines as well as in Kazakhstan and South America.

-- Dow Jones Newswires contributed to this story --