The state-run company will now invest 54.6 billion baht ($1.75 billion) this year, down from 100.9 billion baht, with the majority of the cutbacks involving the company's planned foreign investment, Reuters reported.

The news agency also quoted PTTEP chairman Parnpree Bahiddha-Nukara as saying some of the company's planned projects this year had also been delayed because it will take time to complete mandatory environmental and health impact assessments.

Earlier this year, PTTEP unveiled a five-year investment plan which will see it spend nearly $25 billion by the end of 2017.

Parnpree told reporters on Thursday that the company's five-year investment budget currently remained unchanged, but added that it would be reviewed by the board at a meeting on 3 August.