When merger partners SunTrust Banks and BB&T announced last week the name of their combined bank would be "Truist," the reaction from many on social media was less than kind.

Now a credit union from BB&T’s hometown of Winston-Salem, N.C., has responded with a lawsuit alleging Truist is too close to its own name: Truliant.

Truliant Federal Credit Union filed suit Monday alleging trademark infringement against Atlanta-based SunTrust and BB&T. Truliant alleges consumers might confuse the two names and products the credit union markets under the “Tru” prefix of its trademark. These marks include its Tru2Go mobile banking app and “Truceratops,” a thumbs-up-waving dinosaur that’s the face of the credit union’s Dino Dollar children’s savings club.

“This is a clear infringement on our name, and their proximity to our main business region will confuse consumers and undermine the trust we have built in our institution,” Truliant President Todd Hall said in a news release.

“As a member-owned cooperative and community leader, it is very important for consumers to be able to make this distinction.”

The lawsuit pits what’s soon-to-be the nation’s sixth-largest bank with more than 3,000 branches and $442 billion in assets against a credit union with about $2.6 billion in assets and 32 branch locations.

SunTrust and BB&T announced in February plans to create the nation’s sixth-largest bank. Truist Bank will be based in Charlotte. Atlanta will be home to the combined bank’s commercial operations and Winston-Salem will be the home of Truist’s community bank. The merger is expected to be completed later this year but it will take some additional time for the new bank to rename its branches and for the Truist name to appear on Suntrust Park in Cobb County.

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The companies hired Interbrand, a well-known branding agency, to craft a new identity. The Truist name was formed with input from SunTrust and BB&T employees and the banks’ clients through focus groups and other research. A logo and colors for Truist Bank haven’t been released.

“The companies conducted a rigorous process to research, select and secure the new name,” SunTrust spokesman Mike McCoy said in a statement. “Beyond that, we do not comment on pending litigation.”

The lawsuit filed in a federal court in North Carolina is just one example of the types of snags that can hit companies when they merge or change names.

“It’s really difficult to find a name that is neither generic, which means anyone can use it and that’s a bad thing, or that doesn’t impede on anybody else’s trademark,” said Ken Bernhardt, a former Georgia State University marketing professor and consultant.

“It’s why many companies coming up with a brand come up with a word that doesn’t exist.”

Bernhardt said it’s unusual for a rival company to sue before a logo and colors are announced and before any potential harm might be assessed. That might make what will already be a high bar for Truliant to prove harm even higher to clear.