For example, since the start of 2012, banks and thrifts announced 13 deals involving 20 or more branches including four deals in 2014 through mid-October. By comparison, from 2002 through 2011 SNL found only 11 deals involving 20 or more branches.

So far in 2014, banks have announced sales involving 119 branches in Illinois, the most of any state this year due to the Royal Bank of Scotland Group's sale of 103 branches to U.S. Bancorp in the Chicago area, according to SNL.

Texas was second with deals that involved 49 branches because of Citigroup's sale of 41 branches in the Lone Star state to BB&T.  This followed BB&T's December 2013 agreement to purchase another 22 of Citi's Texas branches.

Michigan and North Carolina were tied for third with deals that included 24 branches announced in 2014 to date. California rounded off the top five with deals that involved 22 branches.

In 2013, Texas was the state with the most branches being sold — 32. New York was second with 26 branches, Washington was third at 23, followed by Michigan with 21 and Iowa at 19.

According SNL, Bank of America is the leading branch seller so far this year.

Since the start of 2014,  BofA  completed the sale of 84 branches, 64 of which were in deals announced this year. The company announced deals for 43 additional branches in 2014 that are still pending.

From the beginning of 2012, BofA has sold 285 branches in 21 states, which included 44 branches in Michigan, 32 in New York, 25 in Missouri and 19 in Washington. The bank has sold double-digit branches in nine other states as well, SNL said.

Unlike BofA and Citi, JP Morgan Chase & Co. and Wells Fargo have not participated in the recent branch divestiture wave, the SNL analysis noted.

BofA reduced its branch network by 305 branches between July 2013 and June 2014 and Citi cut 81 branches. JPMorgan cut only 15 branches while Wells Fargo added 16 branches.