* Uniper's 48.24 pct stake valued at 500 mln eur -sources
* OLT Offshore LNG Toscana has high share of regulated sales
* Macquarie, First State seen as interested-sources (Adds details on OLT, interested parties)
By Stephen Jewkes and Christoph Steitz
MILAN/FRANKFURT, Feb 3 (Reuters) - Germany's Uniper UN01.DE has hired Goldman Sachs (NYSE:GS) GS.N to sell its stake in a liquefied natural gas (LNG) terminal in Italy, a deal that could value the whole business at 1 billion euros ($1.1 billion), three people familiar with the deal told Reuters.
Books have been opened for due diligence on OLT Offshore LNG Toscana's business and a deal could materialise in the first half of 2017, the people said, also adding that there was no guarantee that a sale would take place.
Energy firm Uniper holds a 48.24 percent stake in the OLT terminal, while Italian utility group Iren IREE.MI owns 49.07 percent. The remaining 2.69 percent stake is held by U.S.-based shipping group Golar LNG GLNG.O .
"It's a regulated asset so there should be healthy demand," one of the people said.
With a regulated asset base of about 900 million euros and 64 percent of revenues guaranteed, OLT shares characteristics with regulated power and gas grids that have met with strong interest from infrastructure investors.
The terminal is expected to attract established players, including Macquarie MQG.AX as well as First State Investments, the asset management arm of Commonwealth Bank of Australia (CBA) CBA.AX , the people said.
OLT started commercial activities in late 2013 and can handle LNG - which is frozen at minus 163 Celsius (-261 Fahrenheit) to significantly reduce volume - from carriers with a capacity of 65,000-155,000 cubic metres.
The high density means large volumes of LNG can be transported by ship, thereby reducing reliance on pipelines from Russia and North Africa.
Uniper's stake in OLT could be valued at about 500 million euros, the people said, putting a price tag of about 1 billion on the whole business with a capacity of 3.75 billion cubic metres a year, about 4 percent of Italy's requirement.
Iren Chief Executive Massimiliano Bianco in October also hinted at strategic options for the group's OLT stake, which he said was not strategic, adding Iren would assess what to do with it in the coming months.
Iren recently said its stake was worth 476 million euros.
Uniper, Goldman Sachs, OLT, Iren, Macquarie and First State declined to comment. Golar LNG was not immediately available for comment.
The deal would help Uniper, which was spun off from E.ON EONGn.DE last year, to reach its target of selling at least 2 billion euros in assets by 2018, a plan that is likely to include its stake in Brazil's Eneva ENEV3.SA . ($1 = 0.9247 euros)