STAKES in mining firms fell around the world as traders considered the potential impact of a rent tax on the Australian extraction industry.

Last week, Merrill Lynch and Co warned that the 40 percent resource rent tax approved Sunday, may cut the earnings of Rio Tinto by as much as 30 percent and BHP Billiton’s by 19 percent.

As markets anticipated Australia’s decision on the reform, which takes effect in 2012, stocks in Rio Tinto fell 4.36 percent to 3,379 pence (US$51.64) in London, making it the FTSE 100’s second-biggest faller on Thursday.

BHP Billiton, the firm defended by Prime Minister Hun Sen at the Government-Private Sector Forum on Tuesday over accusations of graft in its former concession in Mondulkiri, saw its stock price decline again in Sydney. On April 23, BHP stock price was A$41.97 (US$38.88) declining to A$40.7 at close of play Friday.

Meanwhile Australian miners Southern Gold saw stock sink by 8.33 percent in Sydney on Friday, to A$0.11, after the release of its activity and cash flow reports for the first quarter, which included an update on its gold concession in western Cambodia.

InterContinental Hotels Group rode to the top of the FTSE 100 leader board in London on Thursday after a daily rise of 6.1 percent, before closing slightly down at 1,159 pence (US$17.70) by Friday evening.

Bloomberg reported that the group, which runs a hotel in Phnom Penh, expects a revenue per available room spike at its Holiday Inn chain by as much as 7 percent after a renovation of the brand.