SYDNEY, March 12 (Reuters) - Voters in iron ore-rich Western Australia turned against the governing centre-right Liberal party on Saturday, in a state election result set to derail billions of dollars of privatisations including a port and major energy grid.
The opposition state Labor party, which campaigned against the government's plans to sell a majority stake in the A$15 billion ($11.3billion) Western Power electricity grid along with privatisation of the $1.5 billion Fremantle Port, won decisively and will govern without needing a coalition partner.
The result puts a dent in the country's privatisation plans, with the Australian government encouraging the states to sell assets by offering them up to A$5 billion in cash grants if they then quickly re-invest proceeds in infrastructure projects.
Outgoing Liberal Premier Colin Barnett conceded defeat on Saturday evening. He said voters wanted a change after his eight-and-a-half years in power.
"At the end of the day, time was probably the factor," he told supporters at an event in the state capital of Perth.
Barnett was the country's longest serving political leader, having seen four changes of Prime Minister during his tenure.
The period has included huge swings in iron ore prices - the state earns money from charging miners royalties - that saw Western Australia shift from enjoying the strongest economy in the country to languishing with its weakest.
Western Australia has forecast a A$3.39 billion budget deficit this year, with the planned sales of major state-owned assets one of the ways it had intended to pay down debt.
The Mark McGowan-led Labor party is predicted to win 40 seats to the Liberal's 19, the Australian Broadcasting Corporation forecast, with 60 percent of the votes counted.
Pauline Hanson's One Nation party recorded less than 5 percent of the vote. The state election was the first major test of the popularity of the Far Right leader after she won a place in the federal parliament last year. ($1 = 1.3303 Australian dollars) (Editing by Alexander Smith)