KUALA LUMPUR (REUTERS, BLOOMBERG) - Malaysian Prime Minister Muhyiddin Yassin on Saturday (June 6) appointed Mr Wan Zulkiflee Wan Ariffin, the president and chief executive officer of state oil firm Petroliam Nasional Bhd, as chairman of Malaysia Airlines.

It was also announced that Mr Tengku Muhammad Taufik Tengku Aziz, the executive vice president and group chief financial officer at Petronas, will take over as group CEO of the energy company.

Mr Muhyiddin said in a statement from the Prime Minister's Office that Mr Wan Zulkiflee will take over as chairman of the national carrier effective on July 1.

"In a challenging economic environment, there are some state-owned companies that need to be strengthened to meet the world's new normal," Mr Muhyiddin said. "The government will continue to re-look at the leadership in state-owned companies to ensure they are achieving the country's socio-economic objectives."

Mr Wan Zul, as he is known, is a Petronas veteran, joining the company in 1983 as a process engineer and working his way up through the ranks.

He took over in 2015 and led the company through a period of tumultuous oil prices.

Benchmark Brent crude plunged to near 12-year lows soon after he took over, forcing Petronas to cut US$12 billion (S$16.74 billion) from costs and thousands of jobs for the first time.

He also championed an ambitious US$27 billion oil refinery and petrochemical plant joint venture with state-owned Saudi Arabian oil company Saudi Aramco located in the southern state of Johor.

Under his leadership, Petronas also expanded internationally.

As oil prices crashed again this year to below US$20 per barrel and profits fell 68 per cent in the first quarter, Mr Wan Zul said Petronas will optimise costs and international capital expenditure.

Petronas is the sole manager of Malaysia's oil and gas reserves, and a key source of government revenues.