MILAN, Dec 16 (Reuters) - Italy's Snam is considering the sale of a minority stake in its gas storage unit worth up to 6 billion euros and is working with Goldman Sachs and Credit Suisse to study its options, two sources said.

Snam pledged last month https://www.reuters.com/markets/europe/snam-eyes-investments-23-bln-euros-2030-speed-green-drive-2021-11-29 to spend as much as 5 billion euros ($5.7 billion) by 2030 to grow its storage footprint in Italy and abroad, including plans to develop an international green storage platform.

A series of infrastructure funds, including Australia's Macquarie, approached Snam earlier this year about buying into its storage unit Stogit, one of the sources said.

"Snam is studying various options for Stogit including selling a minority stake to a financial investor to help fund expansion plans," the source said.

Things are at a very early stage and no talks are under way, the source added.

As gas prices soar amid strong economic demand and supply-side constraints, gas storage is attracting increasing interest from investors and governments.

Italy is one of the European Union member states that has urged Brussels to build joint strategic sites to help cope with emergency situations in cases of severe scarcity.

Snam, which makes most of its money from transporting gas, is one of Europe's biggest gas storage operators with around 17 billion cubic metres of capacity.

It has pledged to invest more in green gasses such as hydrogen and biomethane and has said its storage sites are already equipped to work with hydrogen.

Stogit, which receives regulated returns on the basis of the investments it makes, has a regulated asset base (RAB) of 4 billion euros.

One of the sources said that following the hefty premium paid by infrastructure fund F2i for Ital Gas Storage, Stogit could be worth between 5-6 billion euros.

All the companies and banks involved declined to comment.

($1 = 0.8826 euros) (Reporting by Stephen Jewkes; editing by David Evans)