MILAN, Dec 13 (Reuters) - The top shareholder in BPER Banca said on Monday it viewed positively further expansion at the Italian bank but growth could not "be an end in itself".

Speaking at the FABI banking union's annual conference, Unipol CEO Carlo Cimbri said BPER could not chase the idea of "a third or fourth large banking group in the country, which is something newspapers love to write about".

Unipol is the top shareholder in BPER with nearly 20% and has been the driving force behind BPER's decision to acquire branches as part of last year's Intesa-UBI merger, a move which has increased BPER's assets by 40%.

Asked about BPER's possible interest for troubled rival Carige, Cimbri said BPER was focused on integrating the new branches and "it'd better concentrate on that".

On the contrary, BPER could be a good merger candidate for Popolare di Sondrio, a regional bank of which Unipol owns 9.5%, Cimbri added.

He said Unipol would support any decision Popolare di Sondrio decides to take once it sheds its cooperative status and its management will be free to assess alternatives.

"If Popolare di Sondrio opts to look at mergers we think that given its history BPER is very well placed," Cimbri said. (Reporting by Valentina Za; editing by Agnieszka Flak)