(Adds details on Codelco earnings, sovereign wealth fund)
SANTIAGO, July 30 (Reuters) - Chile posted a fiscal deficit of 0.3 percent of estimated gross domestic product in the first half of 2015, the government's budget office reported on Thursday, due to weak copper revenue.
The deficit was the equivalent of $792 million. Chile is the world No.1 copper producer and has suffered as prices languish at multiyear lows due to worries over demand in key buyer China.
The fiscal deficit in the second quarter was 0.4 percent after a slim 0.1 percent surplus in the first three months of the year, the budget office said.
State-run copper miner Codelco, which is grappling with a strike by contract workers that has led to the suspension of one small mine, recorded a 35.7 percent fall in revenue in the first half from a year earlier, the budget office said.
Chile closed the first six months of 2014 with a fiscal deficit of 0.1 percent, and reported a shortfall of 1.6 percent of GDP for the whole year.
Meanwhile, the country's rainy day sovereign wealth fund fell in value to just under $14 billion by the end of June, compared to $14.7 billion at the end of last year.
Reporting by Felipe Iturrieta; Writing by Richard Lough in Buenos Aires; Editing by Bernadette Baum