By Barry Malone

ADDIS ABABA (Reuters) - An Ethiopian rebel group said on Tuesday it had killed 267 soldiers since the beginning of October, in its first such claim since the government signed a peace deal with one its factions last month.

The Ethiopian government denied the claim.

The Ogaden National Liberation Front (ONLF) wants more autonomy for the country's mainly ethnic-Somali Ogaden region and has warned foreign companies exploring for oil and gas to stay away or face attack.

Firms, including Petronas and Vancouver-based Africa Oil Corporation, are working in the Ogaden. Petronas has asked for government approval of a deal to sell all its oil and gas concessions to locally-owned SouthWest Energy (H.K.) Ltd.

Commercial amounts of oil and gas have not yet been extracted.

"The ONLF army is continuing its offensive against Ethiopian Army troops in the Ogaden," the faction led by former Somali navy chief Admiral Mohamed Omar Osman said in a statement, detailing dates and places of attack.

"During the months of October and the beginning of November it has conducted 34 tactical and strategic military operations, killing 267 Ethiopian Army soldiers and wounding 157."

"OUTRIGHT LIES"

Ethiopian government spokesman, Shimeles Kemal, described the statement as "the usual outright lies."

Regular claims of attacks from the rebels and denials from the government are hard to verify as journalists cannot travel in the region without government escorts.

The Ethiopian government signed a peace deal last month with an ONLF faction led by Selahadin Mao that claims to represent 80 percent of the group's fighters.

The Osman group claimed responsibility for a 2007 attack on an oil exploration field owned by a subsidiary of China's Sinopec Corp that killed 65 Ethiopian soldiers and nine Chinese oil workers.

Analysts say the rebels have been weakened since 2007 and, while not capable of ousting the government, can frustrate development with hit-and-run attacks.

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