Qatar s Energy Minister and president and CEO of QatarEnergy Saad Sherida al-Kaabi (R) and Claudio Descalzi, CEO of Italian multinational oil and gas company ENI, attend the signing ceremony for their joint venture. AFP
Eni will own a stake of just over three percent in the $28 billion North Field East project, Qatar Energy's CEO said at a signing ceremony in Doha.
Qatar announced France's TotalEnergies as its first, and largest, foreign partner on the development last week, with a 6.25 percent share.
More companies are set to be named.
"Today I'm pleased... to announce the selection of Eni as a partner in this unique strategic project," said Energy Minister Saad Sherida al-Kaabi, who is also president and CEO of state-owned Qatar Energy.
The project's LNG -- the cooled form of gas that makes it easier to transport -- is expected to come on line in 2026. It will help Qatar increase its liquefied natural gas production by more than 60 percent by 2027, TotalEnergies chief executive Patrick Pouyanne told AFP last week.
Russia's invasion of Ukraine has injected urgency into efforts around the world to develop new energy sources as Western countries try to reduce their reliance on Russia.
On Friday, Eni said it would receive only 50 percent of the gas requested from Russia's Gazprom, the third day running of reduced supplies. Rome has accused Gazprom of peddling "lies" over the cuts.
"We have a lot of things to learn from your leadership and also from your standards and from your ability to adapt to very difficult circumstances," Eni CEO Claudio Descalzi told his Qatari counterpart.
Qatar Energy estimates that the North Field, which extends under the Gulf sea into Iranian territory, holds about 10 percent of the world's known gas reserves.
Kaabi refused to divulge how many more partners will be announced. Industry sources have discussed ExxonMobil, Shell and ConocoPhillips, while Bloomberg reported this week that Chinese companies were in talks.
South Korea, Japan and China have become the main markets for Qatar's LNG but since an energy crisis hit Europe last year, the Gulf state has helped Britain with extra supplies and also announced a cooperation deal with Germany.
Europe has in the past rejected the long-term deals that Qatar seeks for its energy but the Ukraine conflict has forced a change in attitude.
"Qatar is the lowest cost source of supply at the moment and therefore it's attractive to the majors (companies)," Daniel Toleman, an analyst at resources consultancy Wood Mackenzie, told AFP.
"So these companies want to be involved in those projects."