Thai oil firm PTTEP will keep its license and will be allowed continuous but monitored operations in Australia despite the 2009 Montara oil spill incident in Timor Sea.

Ensuing investigations that followed the disaster showed that PTTEP holds major culpability but the findings did not prevent Federal Resource Minister Martin Ferguson from giving the company a new lease in life.

Ferguson said that while PTTEP was given another chance, the firm will be operating under strict scrutiny by his ministry and any infractions, even minor ones, would lead to final cancellation of the company's license to operate.

Strict conditions will have to be followed by the Thai energy firm for the next 18 months and Ferguson stressed that his office will keep close watch on the behaviour and operations of PTTEP.

The resource minister said that PTTEP has committed to implement significant changes as he revealed that "this company is on essence on notice- you either meet the requirements expected by the Australian community or your social licence to operate in Australia will disappear."

However, Ferguson's decision came as a surprise for Greens Senator Rachel Siewert, who declared that "I find it really hard to fathom why the Government thinks it's acceptable that this company should be allowed to bid for and be given any new leases when it has yet to demonstrate it can manage its existing operations."

Also, the World Wildlife Fund Australia expressed its disappointment on the outcome of the incident that is considered as the worst oil spill in history.

WWF's Paul Gamblin could not understand why PTTEP was allowed to stay on the business considering the magnitude of its responsibilities, which he said the company apparently neglected.

In light of the decision, the WWF urged the federal government to hold off any oil and gas explorations in Australia pending the implementation of systemic changes that would avoid the recurrence of the disaster.

The decision, according to Gamblin, is a "a continuation of the Wild West approach unfortunately to oil and gas development in this country and I think the Australian community will be very disappointed with this response."