Adds context and analyst comment in paragraphs 5-6

Dec 2 (Reuters) - French market research firm Ipsos ISOS.PA said on Monday it was in talks with Kantar Media over a potential acquisition of the London-based group, confirming a Reuters report from Friday.

"There can be no certainty that any offer will be made, nor as to the terms on which any such offer might be made," Ipsos said in a statement.

Ipsos is preparing a binding offer to buy the TV ratings data business from market research group Kantar, two people with knowledge of the matter told Reuters.

Any deal involving Kantar could be worth more than 1 billion euros ($1.05 billion), one of the sources said.

Kantar's largest shareholders are U.S. private equity firm Bain Capital BCSF.N and advertising giant WPP WPP.L, with respective stakes of 60% and 40%.

"From WPP's perspective, Kantar does not contribute to its earnings as it is effectively held as an 'investment' rather than an associate," Citi analysts said in a note, adding there would be questions over shareholders' returns if a deal is reached.

Shares in Ipsos, listed and headquartered in Paris, fell more than 2% by 0815 GMT, touching their lowest price in more than a year.

The French group, which provides consumer market research services and has become a household name globally for its opinion and election polls, has a market value of 1.9 billion euros.

($1 = 0.9522 euros)

(Reporting by Gianluca Lo Nostro in Gdansk; editing by Milla Nissi)

((gianluca.lonostro@thomsonreuters.com;))