Athens-based The National Bank of Georgia, which has a Gainesville office, is now part of State Bank Financial Corporation of Atlanta.

State Bank Financial, the holding company for State Bank and Trust Co., announced the merger on Tuesday.

The National Bank of Georgia has a bank at 500 Jesse Jewell Parkway.

State Bank also announced a merger with S Bankshares Inc. The mergers were completed on Dec. 31.

State Bank operates 31 full-service banking offices in Atlanta, Middle Georgia, Augusta, Athens, Gainesville and Savannah, and eight mortgage origination offices throughout Georgia.

“We are pleased to welcome our new clients and team members from The National Bank of Georgia and S Bank,” State Bank CEO Tom Wiley said in a news release.

“These mergers provide for the expansion of our statewide footprint with entry into the very attractive markets of Athens, Gainesville and Savannah. With these transactions completed, we have crossed over $4 billion in total assets and have banking offices in seven of the eight largest markets in Georgia.”

The conversion of National Bank of Georgia’s and S Bank’s operating systems into State Bank’s operating system is expected to be completed in early February, according to the news release.