* Foreign oil firms still wary of security after 2011 war
* Libya has 15,000-strong oil protection force
* Clashes at Libyan gas complex, other oilfields last month
TRIPOLI, April 10 (Reuters) - Libya will not allow any foreign security presence at its oilfields, the head of the state energy firm, the National Oil Corporation (NOC) said, even though many international firms active in the country are still wary about post-war violence.
Some 18 months after the ouster of Muammar Gaddafi in the 2011 war, Libya's new rulers have struggled to impose their authority on a country awash with weapons and where militias often have more power on the ground than state security forces.
In a statement posted on its website, the NOC quoted its chairman, Nuri Berruein, as saying Libya "will not allow foreign security presence of any form at oil installations."
It said Berruien made the comments during a meeting with a delegation from BP in Tripoli on Monday to discuss security at the company's oil sites in Libya.
BP said in late January it was reconsidering plans to drill for oil in Libya due to heightened security fears following an attack by Islamist militants on the In Amenas gas plant in neighbouring Algeria earlier that month.
BP was due to resume exploratory drilling in western Libya that was suspended during the 2011 war. The NOC quoted BP security official Derek Porter as saying another delegation would travel to Libya next week for more talks on security.
Following the In Amenas attack, OPEC member Libya said it had strengthened its oil protection force in southwestern oilfields near the Algerian border.
Since the end of the war, it has set up the 15,000-strong Petroleum Facilities Guard to secure installations, made up mainly of former rebel fighters but they have at times fought among themselves.
Last month violence erupted between rival factions of the force over who should control security at two eastern oilfields. This came after armed clashes at the Mellitah gas complex, a joint venture between the NOC and Italy's Eni, halted Libyan gas exports to Italy for several days.
Foreign oil firms were the first to return to Libya after the 2011 conflict, helping the North African country return close to pre-war output levels of around 1.6 million barrels per day. But production has at times fallen due to disruptions caused by protests. It now stands at 1.55 million bpd.
However, oil services firms which Libya needs as it seeks to increase output, have been slow to come back.
The NOC statement quoted Oil Minister Abdelbari al-Arusi as saying: "The security situation continues to improve, despite being amplified by the media." (Reporting by Hamid Ould Ahmed in Algiers and Marie-Louise Gumuchian in Tripoli; writing by Marie-Louise Gumuchian; editing by James Jukwey)