MELBOURNE (Reuters) - BHP Billiton (>> BHP Billiton Plc) will not move its low tax-paying Singapore marketing hub even if Australia goes ahead with plans to cut corporate taxes, Chief Executive Andrew Mackenzie said on Thursday.

BHP's Singapore office is the focus of a long-running fight with Australia's tax office, which argues the company is shifting profit to Singapore on the sales of its mostly Australian products to minimise tax.

Mackenzie reiterated the company has to base its marketing operations in Singapore to be close to its customers, most of whom are in Asia, and would not move it to Australia.

"If we weren't in Asia, doing that job would be much harder for our people. We would have less customer contact and we'd be less effective at selling more volumes out of Australia for higher prices," he said in an interview on Australian Broadcasting Corp radio.

Australia's conservative government wants to cut the company tax rate to 25 percent from 30 percent to make the country more competitive, following in the footsteps of the United States, where the rate has been cut to 21 percent.

Mackenzie said a lower tax rate would spur BHP to invest in more projects in Australia, small and large.

"We have plenty of opportunities to invest in Australia. We will pursue many of them, but we will pursue more if the tax rate were lower," he said.

(Reporting by Sonali Paul; Editing by Tom Brown)

Stocks treated in this article : BHP Billiton Plc, BHP Billiton Limited