Singapore’s main index fell by midday, reversing earlier gains, dragged by heavy losses in palm oil firm Wilmar International’s shares, which tumbled to over a three-year low.

Wilmar tumbled as much as 6.4 percent to S$3.21, its lowest level since April 2009, on market talk China has told edible oil suppliers to keep prices stable. Wilmar is the worst performing stock on the Straits Times Index (STI) this year, falling 35.6 percent since the start of 2012.

Wilmar said in an email that there was no control on cooking oil prices in China, but “the government has advised that companies should avoid increasing prices unless it is absolutely necessary.”

Over the last 60 days, analysts have cut EBITDA estimates for Wilmar this year by an average of 2 percent and earnings per share estimates by 4.7 percent, Thomson Reuters’ StarMine data showed.

The benchmark STI was down 0.2 percent at 2,999.62 points, reversing from an intraday high of 3,029.53 and underperforming its regional peers. The MSCI Asia Pacific ex Japan was up 1.8 percent, after comments from the European Central Bank President signalled its resolve to defend the euro zone.