Nigeria’s state-run oil company will keep buying cheaper, lower-quality petrol for now because the government has yet to circulate new rules forcing a switch by July to cleaner fuels with less sulphur content, Times of India reports.

Nigeria, an oil producer that relies on imports of refined fuels, had said it would raise standards for petrol and other fuels imports from July 1, a move backed by the U.N. Environment Programme which has pushed for using cleaner fuel in the region.

With the government yet to issue rules that specify new fuel standards, traders said NNPC was likely to pick the cheaper fuel grades with more sulphur under the crude for refined products signed in recent days between itself and major traders, after the July deadline has passed.

The lack of government guidance casts doubt on plans to import cleaner fuel for the rest of the year as NNPC was under no obligation to buy the more expensive petrol, the trading sources said. “They will have to issue circulars and new specification sheets,” one importer said, adding none had yet been sent out.