Talk about an awkward situation.

BNC Bancorp (BNCN) has been busy integrating its systems with those of Randolph Bank & Trust, which it bought in October. Oddly enough, a glitch in the process created problems for a rival bank, Carolina Bank Holdings (CLBH) in Greensboro, N.C., that was in no way involved in the M&A deal.

A message that was supposed to appear on the old Randolph Bank website to direct its customers to their new bank, BNC, accidentally appeared on the Carolina Bank website. An error made by technology vendor Fiserv was the culprit, officials at BNC and Carolina Bank said.

Fiserv was Randolph Bank's core processor and, during the conversion process, "must have incorrectly made a change on the Carolina Bank system, which only they had access to, when it possibly intended to make the change on the Randolph Bank system," says David Spencer, BNC's chief financial officer.

Fiserv did not return calls seeking comment.

Carolina Bank officials noticed the error Saturday afternoon and had to determine whether the cause was hacking or something else, says Bob Braswell, the chief executive of Carolina Bank. The company quickly posted a note on its home page flagging the error, which had been resolved by Monday morning.

"We understood that it could have created some customer concerns, so we updated our website and put a notice on our Facebook page," Braswell said.

Braswell and his team also spent some time over the weekend getting employees "settled down," since the message also led to some speculation that Carolina Bank might be selling itself to BNC. "I told my folks that we'd be more professional announcing something like that," he says.

BNC, which is based in nearby High Point and has branches in Greensboro, agreed to buy Randolph Bank in July. Most systems integrations have snags, but it is rare for one to create headaches for an unrelated financial institution.