An oil consortium led by Italy's Eni group agreed on Monday with Kazakhstan authorities to continue talks aimed at settling a dispute over a huge Caspian Sea site.
Monday was the deadline previously set for reaching an amicable agreement on cost over-runs, start-up delays and profit sharing.
The Agip KCO consortium - which includes Total, Exxon Mobil, Royal Dutch Shell, ConocoPhillips, Impex and Kazkhstan's oil company KazMunaiGaz - issued a statement saying talks would continue "in a positive and constructive spirit of cooperation".
They said they had signed a memorandum of understanding on the Kashagan field - the world's largest oil find in 30 years.
"The parties have also agreed on the framework within which the talks will be held," the statement said.
The statement made no mention of a Russian news agency report that KazMunaiGaz had already managed to double its quota to some 16% - or that Exxon Mobil reportedly opposed this.
The agreement to keep talking comes two weeks after Italian Premier Romano Prodi's visit to the Kazakh capital here, which was seen as paving the way for a solution to the dispute.
After Prodi had talks with Kazakh President Nursultan Nazarbayev, Eni CEO Paolo Scaroni said he saw an end to the row "by the end of the year".
But Scaroni admitted negotiations would still be "complex".
The Eni chief denied rumours that Russian giant Gazprom might be behind Kazakhstan's recent strictures on Kashagan.
Kazakh authorities suspended work at Kashagan for three months at the end of August, citing a fresh start-up delay - from 2008 to 2010 - and cost over-runs that have pushed the consortium's budget up three-fold.
Scaroni said the consortium would issue a new budget at the end of the year and voiced confidence that a Kazakh parliamentary bill on mineral rights, which might loosen the consortium's hold on Kashagan, would not be approved.
Problems such as dealing with dangerous gases, drilling under the sea and bringing in expensive new machinery have dogged the Kashagan project, which was initially supposed to come on line in 2005.
When it announced the three-month moratorium on August 27, Kazakhstan accused the consortium of environmental and customs irregularities.
For some time Kazakhstan has been threatening to revoke the consortium's license.
As well as the cost over-runs and start-up delays, Kazakh pressure to up its profit quota is also involved in the dispute, which echoes Russia's wrangle with Shell over an operation eventually taken over by Gazprom.
The consortium plans to extract 7-9 billion barrels of oil from Kashagan's estimated 38-billion-barrel field.
The Financial Times recently said Kazakhstan "might" go as far as ejecting the consortium but this was unlikely because it needed its expertise.
