China Petroleum & Chemical (Sinopec) is in the midst of its "most difficult year ever" and the worst will come in the second half, chairman Su Shulin said.

The company's refining business will continue to be under pressure, with declines in crude oil prices probably offset by a reduction in government subsidies, Su said.

"This year is the most difficult year ever for Sinopec. And the worst situation is expected to come in the third and fourth quarters," Su told a press briefing today following the company's interim results announcement.

Sinopec suffered a 77 percent decline in first-half profit.

"We can't see any chance of a turnaround in the refining business unless international crude oil prices drop steeply," the chairman said.

The company expects crude oil prices to stay relatively high in the second half despite the recent correction.

Though mainland regulators said this month that the government would pay "appropriate" subsidies to cover some of Sinopec's refining losses in the third quarter, the company expects them to be lower than the quarter before, Su said.

Government-controlled prices of some domestic refined products were raised in June.

Chen Ge, secretary of the board, said value-added tax rebates on purchases of imported refined products will also be paid out for the third quarter.

In the second quarter, Sinopec booked subsidies of 22.93 billion yuan to cover processing losses and 3.07 billion yuan in VAT refunds on refined-product imports.

Chen said the company had yet to be notified of any further price rises in domestic refined products in the third quarter, despite market talk that increases are possible.