Fast-growing State Bank and Trust in Macon, Ga., has purchased substantially all of the assets of Altera Payroll, a payroll services company, to diversify its revenue stream.

State Bank has taken advantage of the many bank failures in its home state, acquiring a dozen failed banks since 2009, including the $2.8 billion-asset Security Bank Corp. and its six subsidiaries. State Bank's last deal was for the failed Community Capital Bank in Jonesboro, Ga., in October 2011.

The acquisition of Altera in Macon will "diversify State Bank's revenue beyond its existing lines of business," the bank said in a news release Tuesday.

Altera, which will operate as a division of State Bank, focuses on the payroll needs of small and midsize businesses. Its management team has worked together for more than 11 years, previously running the payroll processing group for the former Flag Financial in Atlanta. Flag was led by Joe Evans, chairman and chief executive of State Bank, and other State Bank executives before its sale in 2006 to RBC Centura Banks.

State Bank, a unit of the $2.7 billion-asset State Bank Financial (STBZ) in Atlanta, will retain the Altera name and its 18 employees. The financial terms of the deal were not disclosed.

"State Bank is focused on deepening its relationships with its customers. Adding a best-in-class payroll services team creates a natural extension for those relationships," Evans said in a news release. "We have known and worked with the Altera team for many years, making this the right opportunity for State Bank."

Sterne Agee & Leach served as financial advisor to State Bank on this transaction.