Malaysian state energy firm Petronas said on Thursday that its net profit fell 45 percent year-on-year in the last quarter of 2012 due to lower demand for crude oil. The country\'s only Fortune 500 company, which contributes nearly half of Malaysia\'s budget revenues, said earnings for the quarter ending December 31 fell to 8.7 billion ringgit ($2.8 billion) from 15.9 billion a year earlier. Petronas had earlier cited sagging prices for a 30 percent and 21.6 percent fall in net profit for the second and third quarter of 2012. For the full year, its net profit fell 14 percent to 59.1 billion. \"Revenue for the quarter declined primarily due to lower crude oil trading volume on the back of limited trading opportunities and the strengthening of the ringgit against the US dollar,\" the company said in its latest financial report. It added that higher operating costs and impairment losses on assets resulted in lower margins for 2012. Revenue for the year was 288.5 billion, just shy of 2011\'s 291 billion. Petronas expects to face \"geopolitical uncertainties, macroeconomic challenges and rising operating costs\" as well as a shortage of talent this year. It said it will focus on \"efficiency and operational excellence\" to deliver a satisfactory performance.Profit had risen more than 62 percent in the first quarter thanks to then-strong crude oil prices, but has fallen since then along with prices.