Stocks to watch on the Australian stock exchange on Thursday, March 12:

AAD – ARDENT LEISURE – down 46.5 cents, or 19.14 per cent, at $1.965

Shares in Gold Coast theme park owner Ardent Leisure Group have dropped sharply during morning trade.

BHP – BHP BILLITON – down $1.58, or 4.95 per cent, at $30.33

RIO – RIO TINTO – down 68 cents, or 1.16 per cent, at $57.87

Australia’s biggest iron ore producers Rio Tinto and BHP Billiton are destroying themselves and contributing to $US50 billion in lost earnings by flooding the market, the head of US-based iron ore producer Cliffs Resources says.

TLS – TELSTRA – up two cents, or 0.32 per cent, at $6.22

The competition watchdog is proposing to cut the prices that other telcos pay Telstra to use its copper network to provide telecommunication services to consumers.