By Amy-Jo Crowley

LONDON, March 29 (Reuters) - ING Groep INGA.AS met with Italy's Banca Popolare di Sondrio BPSI.MI in recent weeks as it seeks to grow in Europe through takeovers, a person with knowledge of the matter said.

The early stage discussions were not advanced and may not proceed to an offer by the Dutch bank, the person said.

ING and Sondrio declined to comment.

A bid by ING would rival a 4.3 billion euro ($4.7 billion) all-share offer by BPER Banca EMII.MI for Sondrio in February, which was the latest in a raft of takeover activity in Italy's banking sector.

BPER and Sondrio both have as lead shareholder Unipol UNPI.MI, Italy's second-largest insurer, which owns nearly 20% of each lender.

Unipol Chairman Carlo Cimbri said on Friday a foreign bank was studying a potential bid for Sondrio to rival BPER's.

Speaking at the presentation of Unipol's multi-year plan, Cimbri hinted at ING as a possible suitor by saying the bank interested in Sondrio was the colour of a journalist's tie, which was orange.

Headquartered in the Valtellina valley, a wealthy mountain area northeast of Milan, Sondrio has enlisted the help of Bank of America and Morgan Stanley as defence advisers against BPER.

The bankers have been speaking with potential bidders, the person said, speaking on condition of anonymity because the matter is private.

Sondrio has already offered to return 1.5 billion euros to shareholders over 2025-2027, doubling the payout of the past three years, in a move to fend off BPER.

BPER said its pursuit of Sondrio was a defensive move given the consolidation wave in the sector.

ING said in February it was looking for opportunities to buy rival banks in major European countries including Italy, Spain and Germany to boost its size.

The Dutch lender has been active as a retail bank in Italy since 2001 and it is a leading digital bank in the country serving 1.275 million clients. It is currently looking to expand its deposit base by offering a 4% return for a year on new accounts opened before the end of May.

($1 = 0.9236 euros)

(Reporting by Amy-Jo Crowley in London. Additional reporting by Elisa Martinuzzi and Valentina Za. Writing and editing by Anousha Sakoui. Additional editing by Mark Potter)

((amy-jo.crowley@thomsonreuters.com))