German used-car dealing platform Auto1 proposed a deal for Scout24's car listings business, the sources said, adding no firm offer was made and that Scout24 currently had no plans to sell or merge the unit.

Auto1 was not immediately available for comment, while Scout24 declined to comment.

"There were informal talks, and Scout24 made it clear that it sees no upside in splitting itself in two and divesting one of the units," one of the sources said.

Scout24 makes substantial synergies - in programme engineering, data analytics as well as for its Finanzcheck unit - from combining its real estate and car listings activities, the person added.

After receiving an approach for the whole company last year, Scout24 hired investment bank Morgan Stanley to explore strategic options, but it has not launched a formal sale process.

Private equity firms Hellman & Friedman and Blackstone this month submitted a joint bid of 43.50 euros per share for Scout24, which its management said was an inadequate price.

Scout24 is best known for its ImmobilienScout24 home listings in Germany and AutoScout24 listings across Europe. Hellman & Friedman acquired a controlling stake from Germany's Deutsche Telekom in 2013, before listing the business in 2015 and subsequently selling all of its shares.

Auto1 last year received a 460 million euro (401.10 million pounds) financial infusion from Japan's Softbank, valuing Auto1 at 2.9 billion euros and supporting the auto trader's international expansion.

Berlin-based Auto1, founded in 2012, buys cars using its vehicle pricing database to calculate an offer within minutes. It then sells the vehicles on to one of its roughly 35,000 dealerships for a commission.

Auto1 is virtually unknown to consumers except through its used car buying arm Wir Kaufen dein Auto (We Buy Your Car) in Germany and similar names elsewhere. It operates from Finland to Romania to Portugal, 30 countries in all, but not Britain.

(Reporting by Arno Schuetze; Additional reporting by Jörn Poltz; Editing by Tassilo Hummel and Mark Potter)