Stocks to watch on the Australian stock exchange:

BHP – BHP BILLITON – down 93 cents, or 3.1 per cent, at $28.77

RIO – RIO TINTO – down $3.34, or 4.4 per cent, at $73.43

FMG – FORTESCUE METALS – down 14 cents, or 2.9 per cent, at $4.65

Shares in the big miners have fallen on concerns about a possible trade war, and news that Australia and other nations exempted from US tariffs will be saddled with steel and aluminium quotas to prevent non-exempted nations attempting find backdoor entry points to America.

CBA – COMMONWEALTH BANK – down $2.06, or 2.8 per cent, at $72.81

Commonwealth Bank and AUSTRAC will enter mediation to attempt to resolve the civil case in which the bank is alleged to have breached money-laundering and terrorism-funding laws.

MYR – MYR HOLDINGS – down 4.0 cents, or 10.1 per cent, at 35.5 cents

Shares in Myer fell to a new all-time low of 35.5 cents, a day after UBS analysts questioned the embattled department’s store chain’s sustainability in current form and major shareholder Solomon Lew questioned online sales figures released in Myer’s recent half-year results.

TCL – TRANSURBAN – down 12 cents, or 1.1 per cent, at $11.05

Australian toll road operator Transurban has expanded its North American toll road operations into Canada, acquiring the A25 toll road and bridge in Montreal, Canada from Macquarie Infrastructure Partners for $C840 million ($A843 million).

VOC – VOCUS GROUP – down 5.0 cents, or 2.1 per cent, or $2.37

Internet service providers Dodo, iPrimus and M2 Commander will compensate almost 6,000 customers after admitting they likely breached consumer law by offering national broadband network speed plans they could not deliver.