The facility is operated by a joint venture between Statoil, BP and state-owned energy company Sonatrach. Statoil said limited production started Friday and representatives were working together with the Algerian government to resume full operations there.
"The safety and security of our people is our utmost priority," Lars Christian Bacher, a vice president in charge of international operations for Statoil, said in a statement. "We will take whatever time needed to conduct all required assessments and reviews and take all necessary precautions before we consider a re-entry of Statoil personnel."
Militants sympathetic to al-Qaida stormed the In Amenas complex in January. The attack was said to be a response to an Algerian decision to let French forces use its airspace for a military intervention in Mali.
At least 37 employees of the companies died the attack on the facility and the raids that followed. Statoil in early February confirmed five employees and BP stated that four of its employees died in the attack.
BP said production at In Amenas was targeted at around 870 million cubic feet per day, making it the largest facility of its kind in Algeria.