MOSCOW - Oil producer Saudi Aramco 2222.SE and Algeria's Sonatrach lowered January's official selling prices (OSPs) for liquefied petroleum gas (LPG) by between 1.6% and 6% from December because of weaker demand for the fuel, traders said on Thursday.

Aramco's January OSP for propane decreased by $10 to $625 a metric ton PRO-OFFCL-SA while butane dropped by $15 to $615 a ton BUT-OFFCL-SA, the traders said.

Propane and butane are types of LPG with different boiling points.

LPG is used mainly as fuel for cars, heating and as a feedstock for other petrochemicals.

Sonatrach cut its January OSP for propane by $35 to $550 a ton PRO-OFFCL-DZ and for butane by $25 to $560 per ton BUT-OFFCL-DZ, traders said. 

Aramco's OSPs are used as a reference for contracts to supply LPG from the Middle East to the Asia-Pacific region.

Sonatrach's OSPs are used as benchmarks for the Mediterranean and Black Sea region, including Turkey.

(Reporting by Reuters Editing by David Goodman)