By Tom Bergin

PARIS (Reuters) - Algeria's state-owned energy firm Sonatrach is not in talks with Russian partners about possible joint ventures, despite Russian assertions of co-operation, Sonatrach's chief executive said on Thursday.

European gas consumers are worried about potential co-operation between two of their largest suppliers.

A memorandum of understanding (MOU) to work on joint ventures, which Russia's gas export monopoly Gazprom and Sonatrach signed in 2006, raised fears about the formation of a version of OPEC, which could limit gas supplies and boost prices.

But Sonatrach Chief Executive Mohamed Meziane said this MOU, which expired last year, was not being revived.

"We tried for nearly a year ... we didn't find opportunities," Meziane told Reuters on the sidelines of the International Oil Summit in Paris.

He said there were no talks on reviving the deal and added Algeria was open to investment.

In February, after Algerian President Abdelaziz Bouteflika met with Russian president Vladimir Putin, Russia's energy minister Viktor Khristenko told reporters: "Gazprom and Sonatrach are now working on options to swap assets and take part in extracting and transporting gas."

When asked why the MOU expired with no opportunities being found, Meziane shrugged his shoulders and said: "Ask Gazprom," before adding, "I don't know."

Meziane added Sonatrach had no plans for swaps of liquefied natural gas cargoes. "We have done one operation, that's all," he said.