A banking institution or an out–of–state bank may establish a branch in this State by: Subject to subsection (b) of this section, opening a de novo branch; Purchasing an existing branch from a bank or an insured depository institution; or Converting former headquarters or retaining former branches following: The purchase of all or substantially all of the assets of a bank or an insured depository institution; or A merger or a consolidation with a bank or an insured depository institution. An out–of–state bank may establish a de novo branch in this State under subsection (a)(1) of this section only if the home state of the out–of–state bank allows a banking institution to open a de novo branch in its state. A banking institution or an out–of–state bank may not establish or maintain a branch in this State on the premises or property of an affiliate if the affiliate engages in commercial activities.