In the past month, two of New England’s largest banks by assets purchased smaller rivals. A third just bought its way onto the top-10 list of largest New England banks with its own acquisition.

That’s a lot of activity in one year, let alone one month. And it’s only June.

At the beginning of last month, Independent Bank Corp., parent company of Rockland Trust Co., announced its intention to acquire Somerville-based Central Bancorp and its bank subsidiary, Central Co-operative Bank.

Just last week, the parent companies of West Springfield-based United Bank and Pittsfield-based Berkshire Bank gave us a one-two punch after announcing – just a day apart – their planned acquisitions of Connecticut-based New England Bancshares (NEB) and Beacon Federal Bancorp in East Syracuse, N.Y., respectively.

United’s deal vaulted it onto the top-10 list of New England’s largest stock banks by assets, coming in at number 10. Rockland Trust and Berkshire already occupy the fifth and seventh spots, respectively, according to SNL Financial – and Berkshire is sure to get a bump of its own after its Beacon Federal purchase.

And let’s not forget about Berkshire’s other recent acquisitions of Hartford-based Connecticut Bank and Trust Co. (CBT) and Needham-based Greenpark Mortgage Co., both of which closed in April.

And we’d be remiss if we didn’t at least mention Gardner-based GFA Federal Credit Union’s March announcement of its purchase of New Hampshire’s Monadnock Community Bank.

Head spinning yet?

Of the three most recent acquisitions, Rockland Trust’s purchase of Central Co-op is probably the blandest – if you consider a bank paying $55 million to purchase another bank that nobody else seemed to want bland, that is. Rockland Trust pulled the trigger on the deal, it seems, as almost a pure territory grab.

But United and Berkshire’s own territory grabs merit special attention.

In the case of Berkshire Hills, the Beacon purchase takes it both farther east and west than it has ever been. The Beacon Federal buy gives it contiguous territory just to the west of its already established outpost in Rome, N.Y. – territory it acquired just last year with its acquisition of Rome Bancorp. The deal also gives Berkshire a foothold in Eastern Massachusetts. Beacon Federal operates a branch in Chelmsford, and it will bear watching to see what aggressive Berkshire will do with that kind of springboard.

In all, the deal stretches Berkshire’s total territory to a staggering 45,000 square miles – from Chelmsford in the east to Syracuse in the west; and from Putnam, Vt., in the north to Hartford in the south. In between, there’s a whole lot of room for new branches and regional marketing drives.

United Bank’s deal is interesting from a competitive position. While not exactly quiet on the acquisition front – United acquired Worcester’s Commonwealth National Bank just three years ago – United has nevertheless been overshadowed by Berkshire’s aggression.

When Berkshire was simply consolidating itself in Pittsfield through its acquisition of cross-town rival Legacy Bancorp, or expanding west away from United’s territory with its Rome and now Beacon acquisitions, United may have been content to remain passive.

But after Berkshire made a splash in central Connecticut – just a short hop down Interstate 91 in United’s back yard – no doubt United felt more than compelled to make a counter move, lest it lose its best opportunity for territorial expansion. Acquiring more than a dozen NEB branches in north-central Connecticut is a nice check on the eight CBT branches grabbed by Berkshire.

In all, the dizzying number and impressive variety of financial institution mergers and acquisitions so far in 2012 has been nothing if not impressive. It sets us up for a second half that is sure to bring more fireworks, and not just on July 4.

Kill or be killed. And so far, Massachusetts banks and credit unions are killing it.

In the past month, two of New England’s largest banks by assets purchased smaller rivals. A third just bought its way onto the top-10 list of largest New England banks with its own acquisition.

That’s a lot of activity in one year, let alone one month. And it’s only June.

At the beginning of last month, Independent Bank Corp., parent company of Rockland Trust Co., announced its intention to acquire Somerville-based Central Bancorp and its bank subsidiary, Central Co-operative Bank.

Just last week, the parent companies of West Springfield-based United Bank and Pittsfield-based Berkshire Bank gave us a one-two punch after announcing – just a day apart – their planned acquisitions of Connecticut-based New England Bancshares (NEB) and Beacon Federal Bancorp in East Syracuse, N.Y., respectively.

United’s deal vaulted it onto the top-10 list of New England’s largest stock banks by assets, coming in at number 10. Rockland Trust and Berkshire already occupy the fifth and seventh spots, respectively, according to SNL Financial – and Berkshire is sure to get a bump of its own after its Beacon Federal purchase.

And let’s not forget about Berkshire’s other recent acquisitions of Hartford-based Connecticut Bank and Trust Co. (CBT) and Needham-based Greenpark Mortgage Co., both of which closed in April.

And we’d be remiss if we didn’t at least mention Gardner-based GFA Federal Credit Union’s March announcement of its purchase of New Hampshire’s Monadnock Community Bank.

Head spinning yet?

Of the three most recent acquisitions, Rockland Trust’s purchase of Central Co-op is probably the blandest – if you consider a bank paying $55 million to purchase another bank that nobody else seemed to want bland, that is. Rockland Trust pulled the trigger on the deal, it seems, as almost a pure territory grab.

But United and Berkshire’s own territory grabs merit special attention.

In the case of Berkshire Hills, the Beacon purchase takes it both farther east and west than it has ever been. The Beacon Federal buy gives it contiguous territory just to the west of its already established outpost in Rome, N.Y. – territory it acquired just last year with its acquisition of Rome Bancorp. The deal also gives Berkshire a foothold in Eastern Massachusetts. Beacon Federal operates a branch in Chelmsford, and it will bear watching to see what aggressive Berkshire will do with that kind of springboard.

In all, the deal stretches Berkshire’s total territory to a staggering 45,000 square miles – from Chelmsford in the east to Syracuse in the west; and from Putnam, Vt., in the north to Hartford in the south. In between, there’s a whole lot of room for new branches and regional marketing drives.

United Bank’s deal is interesting from a competitive position. While not exactly quiet on the acquisition front – United acquired Worcester’s Commonwealth National Bank just three years ago – United has nevertheless been overshadowed by Berkshire’s aggression.

When Berkshire was simply consolidating itself in Pittsfield through its acquisition of cross-town rival Legacy Bancorp, or expanding west away from United’s territory with its Rome and now Beacon acquisitions, United may have been content to remain passive.

But after Berkshire made a splash in central Connecticut – just a short hop down Interstate 91 in United’s back yard – no doubt United felt more than compelled to make a counter move, lest it lose its best opportunity for territorial expansion. Acquiring more than a dozen NEB branches in north-central Connecticut is a nice check on the eight CBT branches grabbed by Berkshire.

In all, the dizzying number and impressive variety of financial institution mergers and acquisitions so far in 2012 has been nothing if not impressive. It sets us up for a second half that is sure to bring more fireworks, and not just on July 4.

Kill or be killed. And so far, Massachusetts banks and credit unions are killing it.