The report in the Financial Times Deutschland quotes Mattel's executive vice-president Bryan Stockton.
He said: "Zapf has always been a very strong brand in Germany. We are always interested in strong brands to expand our business" .
Stockton declined to elaborate further, saying only that "we are not commenting on potential takeover talks".
Last year, Zapf signed a partnership deal with Bratz manufacturer MGA Entertainment, which holds a roughly 23 per cent stake in the firm. A Mattel takeover might be seen by many as a bid to hamper MGA's efforts to strengthen distribution of its Bratz brand in Europe through Zapf.