M&T Bank Corp. is nearing a deal to acquire People’s United Financial Inc. for more than $7 billion, in the latest in a string of regional-bank tie-ups.The companies are discussing an all-stock deal that could be announced as soon as this week, assuming talks don’t fall apart. Based in Bridgeport, Conn., based People’s United has a market value of roughly $6.6 billion, while Buffalo, N.Y. based M&Ts is more than 19 billion.Combined, the banks would have more than $200 billion in assets, with a network of branches concentrated in the Northeast and mid-Atlantic regions. The deal would facilitate M&Ts expansion into the Boston market and Strengthen its position in New York and Connecticut.For M&T, a serial obtainer, it would be the first major takeover since its acquisition of Hudson City Bancorp Inc. In 2015. That deal was postponed for three years after regulators found “significant weaknesses” in M&T’s anti-money=laundering and consumer-compliance programs.