TRIPOLI - The government of Libyan leader Muammar Gaddafi has halted all cooperation with Italian energy firm ENI , Libyan Prime Minister Al-Baghdadi Ali Al-Mahmoudi said on Thursday. ENI is the biggest foreign oil company in Libya and has had a presence in the North African country since the 1950s, but it angered Tripoli by suspending operations and establishing ties with rebels trying to overthrow Gaddafi. "We have now ended all cooperation with ENI," Al-Mahmoudi told a news conference in Tripoli. Al-Mahmoudi also said the government in Tripoli was in talks with Russian, Chinese and US firms over new projects in Libya, though he did not give details. He said the Gaddafi government was prepared to let US firms invest because Washington is not taking a direct role in the NATO bombing of Libya. A spokesman for ENI declined to comment. A senior Libyan official told Reuters earlier this month that the governemnt had begun negotiations with Russian and Chinese firms on taking over ENI's projects in Libya after the Italian firm withdrew its staff. ENI, like most other international oil companies with investments in Libya, suspended operations there after violence broke out in February following a rebellion against Gaddafi's rule.