Libya's National Oil Corp on Friday urged all parties to avoid escalation at the El Sharara oilfield, the country's largest, and said it would not restore normal operations until security had been restored.
"Worker safety remains our primary concern," NOC Chairman Mustafa Sanalla said in a statement.
"We urge all parties to avoid conflict and the politicization of key infrastructure."
The eastern-based Libyan National Army said on Wednesday it had seized the 315,000-barrels-per-day (bpd) field from tribesmen and protesters who forced operations to halt when they took the site on Dec. 8.
But an engineer at the field told Reuters that eastern forces were controlling only a pumping substation and that the main production area was still held by armed tribesmen.
The field manager had communicated with all parties in the vicinity of the site and urged restraint, the statement added.
Oil production in Libya, a member of the Organization of the Petroleum Exporting Countries, has been disrupted since conflict broke out in 2011, with protesters and armed groups often targeting oilfields and energy infrastructure.
National production now stands at under 1 million bpd, well below pre-2011 capacity of 1.6 million bpd.