* Berber minority demanding more rights
* Minority blocks port in west, halts gas and oil exports
* Oil output falls further due to protests
* Libya in chaos two years after fall of Muammar Gaddafi
TRIPOLI, Nov 13 (Reuters) - Libya's Berber minority will boycott a committee to draft a new national constitution, the election commission said, in a move that complicate attempts to end oil and gas protests which have dented output.
Members of the Berber, or Amazigh, minority have halted gas exports to Italy and also stopped part of Libyan oil exports by occupying the Mellitah port in western Libya to demand more rights for their long-oppressed people.
The Amazigh, who live in western Libya, demand their language to be guaranteed in the constitution that will be drafted as a step in the country's transition to democracy after Muammar Gaddafi was toppled two years ago.
But attempts by the government and parliament to end the Mellitah protest seem stalling after the Amazigh High Council, which represents their interests, boycotted elections to create the 60-member committee drafting the new constitution.
The struggle for oil wealth, power and representation for the various tribes and militia who helped unseat Gaddafi lies at the heart of Libya's problems as it tries to forge institutions and the rule of law from the debris of more than 40 years of esoteric rule.
A wave of strikes by tribes, militias and autonomous movements blocking oilfields and ports has knocked down output to a fraction of its capacity of 1.25 million barrels a day - reducing the revenue needed for nation building.
The closure of the Mellitah complex, jointly operated by Italy's ENI and Libya's National Oil Corp (NOC), has complicated government's attempts to recover oil production, already curtailed for months by protests at eastern ports
More than 660 candidates registered for the constitutional body, including around 60 women, but no Amazigh candidates were listed despite government attempts to negotiate, the High National Election Commission head, Nuri al-Abbar, told Reuters.
Abbar said he said he would keep open the list for the Berbers open "a day or two" before preparing for the vote.
"At the end we cannot wait any longer," he said. "We need dialogue. We need a solution."
The Amazigh were supposed to get two seats assigned on the body, as do the Tibu and Tuareg minorities, which registered candidates. Six are reserved for women.
Protests are already having an impact on an energy sector attempting to rebuild after the uprising.
Oil output fell further as storage ran almost full at Mellitah, forcing operators to lower production at the 130,000 bpd El Feel field feeding the port to just 18,000 bpd, NOC spokesman Mohamed al-Harari said.
Up to three tankers were waiting outside the port to load, he said.
A shipping source said the port would have to be shut within two days unless a waiting tanker was able to load condensate, a very light oil. Only one tanker has been able to load condensate since the port was blocked in late October.
In Hariga port in Tobruk in the east, strikers demanding autonomy and a share of the wealth prevented another tanker from loading oil at the port under blockage for more than two months, Harari said. Tanks at the port were almost full.
"We have asked the tanker to wait outside the port until we have a good environment for the tanker to load," he said.
In another sign of dissent, former rebels staged a protest at a gas and petrol storage in Sabha in the southern Fezzan on Tuesday, state news agency Lana said. The militiamen said they had not been paid their salaries for almost two years.
In Fezzan, many demand autonomy from Tripoli, like in the east were tribes and militias have seized most oil ports.
The government and parliament seek to hold the vast country together by engaging all regions in drafting the constitution. The committee will be equally split between Tripolitania in the west, Cyrenaica in the east and Fezzan.
Members of the committee will be elected in December or January, Abbar said.
The government has sought to co-opt militias by integrating them into regular forces. But many still have their own agendas - control of local areas, smuggling or demanding better medical care - such as a group of militiamen who blocked the front gate of the Zawiya refinery this week.
NOC spokesman Harari said the 120,000 bpd refinery, which supplies gasoline and diesel for the capital, was producing normally but it might face crude supply problems if a 3-week blockage from the southern El Sharara field continued.