Pre-qualification bids were submitted this week to Shell's Dubai office by contractors in Iran and suppliers in neighbouring Persian Gulf countries.

However, the next step of issuing tenders may take some time, because Shell and its partner Repsol YPF have yet to make a final investment decision on the proposed scheme, which may require an investment of about $10 billion.

Shell said last year it was delaying a final investment decision because of costs and political risk factors.

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