By Dmitry Solovyov
ALMATY, March 18 (Reuters) - A consortium developingKazakhstan's huge Kashagan oilfield said it had appealed a 134.2billion tenge ($737 million) fine by a regional Kazakh authorityfor ecological damage at the site in the Caspian Sea.
The fine adds to the woes of the multinational group, whichhas already spent about $50 billion after numerous delays.
Kashagan, the world's biggest oil find in 35 years, launchedoperations in September 2013 after 13 years of development.Output was then halted in October after gas leaks were detectedin the group's pipeline network.
While output was stopped, residual sour gas was burnt inflares at the project's processing plants, polluting theenvironment, Kazakhstan's Environment Protection Ministry saidthis month..
"We ... appealed the ecological fines," an official for theNorth Caspian Operating Company (NCOC), the venture developingthe oilfield, said on Tuesday.
The appeal was filed at the regional environmentaldepartment of the Atyrau Region in western Kazakhstan, whereKashagan is located.
"Whether we appeal also at national level will be decided ata later stage," the NCOC official said.
Checks showed that the volume of gas flared last Septemberand October was 2.8 million cubic metres, exceeding legallimits, the ministry said at the time.
The consortium, led by Exxon Mobil, Royal DutchShell, Total, Eni and Kazakh stateoil firm KazMunaiGas, also faces a bigger risk thatKazakhstan could seize a bigger stake in Kashagan or refuse toreimburse a big chunk of the money spent to bring it on stream.
Before the gas leaks brought Kashagan output to a halt, theconsortium had failed to achieve so-called "commercial output"at the field by Oct. 1 as stipulated in its contract.
This means NCOC members will not be reimbursed for costsbetween then and the date when they finally achieve commercialoutput, KazMunaiGas head Sauat Mynbayev said this month.
Other NCOC members include Japan's Inpex with 7.56percent and China National Petroleum Corp (CNPC) with 8.33 percent, which it bought from ConocoPhillips lastyear.