Major iron ore producers Rio Tinto and BHP continue to weigh on total shipments from the world-leading Pilbara region of WA.

The four largest WA producers — Rio Tinto (ASX:RIO), BHP (ASX:BHP), Fortescue Metals (ASX:FMG) and Gina Reinhart’s Roy Hill — loaded vessels with a combined 16.57 million deadweight tonnes (dwt) of capacity in the week to 5 June, Argus says.

Loadings were 5 per cent below the average of 17.25 million dwt/week over the past year.

‘Deadweight’ tonnage is the max capacity of the vessel and actually overestimates shipments by around 5 per cent.

Rio Tinto did not ship anything from its ‘East Intercourse Island’ (EII) berths at Dampier for the second week in a row, while BHP is experiencing issues at its ‘Finucane Island’ terminal at Port Hedland.

“Rio has not loaded iron ore at its 45mn t/yr EII terminal since 20 May but has declined to disclose the reason,” Argus says.

“BHP has not shipped from its Finucane Island A berth since 31 May. This follows a pause in shipping from the Nelson Point A berth during 23 May-1 June.

“The firm has been upgrading port facilities to increase its operational flexibility.”

Despite hating our guts, China was listed as the destination for 73 per cent of shipments in the latest week, up from 70 per cent a week earlier.

“After including shipments with unconfirmed destinations — most of which are probably headed to China — the percentage was 81 per cent, up from 77 per cent a week earlier and close to the average of around 82 per cent,” Argus says.

Based on shipping data and average May prices, Westpac estimates WA iron ore exports were worth a colossal $16.7 billion last month.

Prices were sitting at $US203/t yesterday, Argus says, down from $209.30/t on 1 June and from a high of $235.55/t on 12 May.

RIO , BHP and FMG share price charts: