Malaysian Airline System Bhd swung to a third-quarter net loss of 477.6 million ringgit (US$149.98 million) from a profit of 233.2 million a year ago, due to higher fuel costs and an unrealised foreign-exchange loss.

Revenue was 4.9 percent higher at 3.6 billion ringgit from a year earlier, it said in a stock exchange filing.

The airline said its fourth-quarter operational results would be worse than the third quarter as high fuel prices and a weak economic outlook in Europe hurt its business.

"Management is embarking on a significant network rationalisation exercise to withdraw structurally weak, lossmaking routes, and to possibly embark on new higher yielding routes focusing on Asia," it said in a statement.

"We expect the full impact of these initiatives to begin bearing fruit in 2012."

(US$1 = 3.1845 Malaysian ringgit)