Santos (ASX:STO) produced 21.9 million barrels of oil equivalent (mmboe) in the first quarter ended March 31, a 2% rise from 21.5 mmboe in the prior three-month period, according to a Thursday filing with the Australian bourse.

Sales revenue fell 8% quarter on quarter to $1.29 billion, due to lower crude sales volume and lower realised prices for domestic gas and oil-linked liquified natural gas sales contracts, the filing said.

Santos maintained its production volume guidance in the range of 90 mmboe to 97 mmboe for the current year but said its unit production cost in the range of AU$7 per barrel of oil equivalent (boe) to AU$7.50 boe will be elevated in the first half and lower in the second half of the year.

The company's shares were up more than 2% in recent Thursday trade.