By Barry Malone

ADDIS ABABA (Reuters) - Rebel claims that Malaysia's Petronas has stopped oil and gas exploration in Ethiopia are lies and three more firms are in negotiations to start exploration in the country, its mines minister said on Thursday.

Ogaden National Liberation Front (ONLF) separatists and local media said state-owned Petronas had pulled out of the Horn of Africa nation after a gas field it was exploring was overrun by the militants in May.

"The rebels took no gas field," Mines and Energy Minister, Alemayehu Tegenu, told Reuters in an interview. "That didn't happen. Petronas have not ceased operations. They have just suspended work to evaluate their portfolio."

Petronas have yet to comment on the reports.

The ONLF is fighting for independence for the mainly ethnic-Somali Ogaden and has warned international oil and gas companies to stay away or face attack.

Firms including Petronas and the Vancouver-based Africa Oil Corporation are exploring the Ogaden for potential oil and gas reserves. Twelve foreign mineral firms are exploring Ethiopia for deposits.

Apart from a small discovery of natural gas, which Petronas has signed a $1.9 million deal to extract, Ethiopia has not uncovered significant oil or gas deposits.

The government says the Ogaden basin may contain gas reserves of 4 trillion cubic feet and points to oil-producing neighbours such as Sudan and Yemen as evidence there could be major oil deposits under Ethiopia's vast deserts.

Alemayehu said Ethiopia was secure and the government was negotiating new exploration licenses with three foreign firms. He did not name them.

'OUR MILITARY IS IN CONTROL'

"We have no complaints from companies exploring here about our security," the minister said. "We have secured them. Our military is in control."

Alemayehu also said peace negotiations with one faction of the ONLF were at an advanced stage. ONLF spokesmen have denied a deal is imminent.

The Ethiopian government has reported some skirmishes with the rebels in the past six months, but regular accusations from both sides are hard to verify. Journalists and aid groups cannot move in the area without government escorts.

Ethiopian forces launched an assault against the ONLF -- who have been fighting for more than 20 years -- after a 2007 attack on an oil exploration field owned by a subsidiary of China's Sinopec Corp, Asia's biggest refiner.

"Since that attack, we have secured the area," Alemayehu said.

A British geologist was shot dead in the Ogaden last July while working for IMC Geophysics International, subcontracted to Petronas. The ONLF denied involvement and the government said 'bandits' were responsible.

Analysts say the rebels are incapable of ousting the government but can hamper development and weaken security forces in the Ogaden with hit-and-run attacks.

Source: Reuters