* Fund has $67 bln in assets, involved in major litigation

* "Evicted" Tripoli chairman launches legal challenge

* Frozen funds vital to rebuild country after years of war

By Aidan Lewis

TRIPOLI, Oct 2 (Reuters) - A protracted power struggle over Libya's $67 billion sovereign wealth fund risks becoming even more complicated as rival claimants for its chairmanship challenge a bid for control by a U.N.-backed government in Tripoli.

The Libyan Investment Authority (LIA) has been under U.N. sanctions since the toppling of veteran ruler Muammar Gaddafi in 2011. The Security Council has extended the sanctions until July 2017, with diplomats saying they want to see a stable government in Libya before relaxing them.

The LIA was one of several institutions to split after rival governments and parliaments were set up in 2014 in Tripoli and in eastern Libya. Now a government mandated by a U.N.-brokered deal is trying to unite Libya's factions, and is trying to take control of the LIA.

Those contesting authority over the fund say its assets and interests are at risk if managed by the wrong people. Libya's economy is in a state of collapse, and the fund could eventually be an important source of finance for the war-torn country.

Last month, the U.N.-backed Government of National Accord (GNA) appointed a steering committee tasked with overseeing the fund, including its $3.3 billion claims in London courts seeking to recover funds from Goldman Sachs and Societe Generale.

But AbdulMagid Breish, who was appointed chairman in Tripoli in 2013, has resisted the committee's efforts to sideline him.

"We have an absolute mish-mash, a chaotic situation that is duplicated in many other government entities," he said. "We shouldn't be wasting our time with this."

Speaking to Reuters in Tripoli, Breish said he had launched a court challenge against the appointment of the steering committee. He argues it is not legitimate because the GNA's Presidential Council had yet to be endorsed by the eastern parliament.

The newly appointed chairman of the rival, eastern LIA, Fawzi Omran Farkash, has brought a parallel case against the steering committee, Breish said. Farkash could not immediately be reached for comment.

A spokesman for the eastern government, Haitem al-Oraiby, told Reuters that "any decision taken by the Presidential Council is unlawful and unrecognised and therefore the new head of the steering committee is unlawful".

A London-based spokeswoman representing the LIA under the steering committee, Claire Davidson, said the steering committee, appointed by a U.N.-mandated government, was needed to prevent "rogue actions" or any unlicensed attempts to control the LIA and its assets.



"THEY'VE EVICTED ME"

Breish said he refused to cooperate with a handover team that came to the LIA's Tripoli offices to ease the steering committee into place, telling them "if the court says 'yes they (the steering committee) are legal', then I will gladly hand over, and absolve myself of any liabilities".

"I kept on going to my office ... and ultimately the militia that is guarding the building came up to me and said 'we have instructions from the Presidential Council that you should leave your office' ... So they've evicted me."

Breish, speaking at an elegant, private office close to Tripoli's historic centre, said the incident was "quite peaceful". He said the committee would not be able too do much work since most of the LIA's funds were frozen and his signature was still required for any transfers of liquid assets.

The steering committee says Breish illegally reappointed himself after resigning as chairman in 2014 and has no right to sign for payments. Breish says he stepped aside for 10 months after facing a legal challenge, and that the Presidential Council lacks the authority to replace him.

Breish also contends that the steering committee's appointment could hamper efforts to claw back money through international litigation, and undermine his own attempts to reconcile with Farkash. Davidson said the cases against Goldman Sachs and Societe Generale were not at risk.

The steering committee recently hosted a gathering of managers from Tripoli and Malta in Tunis that it called "the first truly integrated and fully attended meeting" of the fund since 2014. Breish was not invited.

(Additional reporting by Ayman al-Warfalli; editing by Patrick Markey, Raissa Kasolowsky and Mark Trevelyan) ((Aidan.Lewis@thomsonreuters.com ; +216-29850352; 00218-945405416))