INTERVIEW-Costs delay Malaysian Petronas' Iran, Sudan plans

* Delaying decision on Iran Pars gas project due costs

* Costs also hit Sudan refinery plan

* No plans to raise stake in Santos Ltd's Gladstone LNG

By Ramthan Hussain and Liau Y-Sing

KUALA LUMPUR, June 9 (Reuters) - Spiralling costs have forced Malaysia's state oil firm Petronas to defer decisions on two major projects, in Iran and Sudan, its chief said on Monday.

Mohd Hassan Marican, CEO of Petroliam Nasional Bhd said Petronas will delay its final decision on investing in Iran's $11.2 billion Pars gas project, as the deadline looms.

"The economic and commercial model that was previously worked on does not make the project viable anymore," he said.

Petronas [PETR.UL] has also deferred for now plans for a 100,000 barrels per day refinery to be built in Sudan, said Hassan.