The state oil fund committee decided on Monday not to halve the subsidy for standard B5 diesel and continue capping the pump price at 32 baht per litre this week.
There is no subsidy on premium diesel.
Energy Minister Supattanapong Punmeechaow announced the decision after chairing the committee meeting on Monday.
He said the committee acted to help keep down the cost of living. The actual price was about 38 baht per litre due to high global oil prices.
Wisak Watanasap, director of the Oil Fuel Fund Office, said the global diesel price was US$160.65 per barrel and the Oil Fuel Fund subsidised the local diesel price at 11.35 baht per litre.
The fund was 66.68 billion baht in the red - 33.26 billion baht for oil subsidies and 33.42 billion baht from its cooking gas subsidy. Its liquidity was only 12.93 billion baht, he said.
The cabinet earlier decided the oil fund should halve its diesel subsidy from May 1. If the subsidy was halved to about six baht per litre, the local pump price would be about 38 baht per litre, which would have a wide effect on people. Therefore, the committee delayed cutting the subsidy, Mr Wisak said.
The country currently consumes about 65 million litres of diesel per day, down from about 73 million litres a day last month, the director said.