By Shadia Nasralla and Sergio Goncalves

LONDON/LISBON, Jan 8 (Reuters) - Portuguese energy firm Galp and private equity-backed Moeve are in talks to combine their refining, chemicals and fuel retail businesses, they said on Thursday, in a deal that, if successful, would create one of Europe's biggest refiners.

Under their non-binding agreement, Galp and Spain's Moeve, whose shareholders are the United Arab Emirates' state-owned investment company Mubadala and U.S. investment firm Carlyle Group, plan to create two new companies.

One would run 3,500 retail fuel stations mainly in Spain and Portugal, selling more than 6.5 million metric tons of refined products annually with ownership split equally.

The other would operate Moeve's Huelva and Algeciras oil refineries and Galp's Sines refinery. The three facilities have combined capacity of around 700,000 barrels per day. Moeve would be the majority owner in the unit, with Galp set to own a minority stake above 20%.

Galp's upstream oil and gas production business, which includes stakes in much-watched, undeveloped oil fields offshore Namibia, would not be included in any merger.

"We expect the key takeaway from the market is that this may increase the likelihood of Galp as a take-out candidate given the cleaner portfolio," said RBC analyst Biraj Borkhataria.

Galp's share price was up 1.4% at 0921 GMT, outperforming a broader index of European energy firms, which was down 1.4%.

(Additional reporting by Stephanie Kelly; Editing by Joe Bavier)