By Ben Glickman |Photography by Andrew Spear for WSJ

Big corporate tie-ups are always delicate affairs, involving integrating systems, replacing signs and branding and making sure a newly combined workforce gets along.

But a nearly $11 billion bank deal last year has an added sticking point: chili recipes.

Following Cincinnati lender Fifth Third's acquisition of Texas-based Comerica Bank, employees from different regions have clashed over the best way to make the dish.

"We got a little bit of an internal civil war here between people who like their chili with beans, no beans or on spaghetti," Fifth Third Chief Executive Tim Spence told Wall Street analysts in April. "So that we're going to have to solve before we can truly say we're one company."

The meat of the issue: Cincinnatians have specific preferences when it comes to chili. Restaurants in the Ohio metropolis serve the meat stew on top of spaghetti or ladled over a hot dog with a huge amount of shredded cheese, a version called a "cheese coney."

Texans are known for their thick, beefy version with no beans and definitely no tomatoes. Chili is believed to have its roots in Mexican cuisine and was popular in the 19th century as a cheap and portable source of protein for cowboys. It's been the state dish since 1977.

Spence's first inkling that chili would be an issue came in his first town hall in Houston after the deal was announced. A Comerica employee asked the chief if he prefers chili with beans or without.

He declined to answer.

He addressed the issue head-on in the next earnings call, saying he was trying to inject some fun into what can be a tedious integration process. He didn't anticipate the response.

After the call, analyst Brian Finneran launched an informal poll on his Bloomberg Terminal in which he queried investors and analysts about their preferences. "Who puts chili on spaghetti?" one responded. "Chili with spaghetti is my only bear case," another wrote.

The reaction prompted Spence to tell Marketing Chief Melissa Stevens they had to organize a bank-wide contest.

Spence is no chili novice.

When he arrived at Fifth Third as chief strategy officer over a decade ago and first addressed his team, someone asked Spence about his preferred chili joint. Spence, who grew up in Oregon, had begun making the rounds of local spots and identified his early favorite. The team approved. "Immediate insider cred," he said.

Last year, when Fifth Third's senior management team held its first chili cookoff, Spence finished second. His recipe in the competition excluded beans but doubled up on onions.

Curt Farmer, the Texas-based former CEO of Comerica and now vice chair at Fifth Third, said Texans are more likely to take up arms over their barbecue style, but chili is a close second. Texans, he said, wouldn't consider a dish made of ground beef, beans and tomatoes to be chili.

While meeting with Fifth Third employees in the Cincinnati area, Farmer has been repeatedly asked if he likes Cincinnati chili — and how he likes it prepared. His introduction to Cincinnati chili was a "three-way" — spaghetti, chili and a large amount of shredded cheese. The verdict? "I really like it."

The chili connections run deep at Fifth Third.

The restaurant chain Skyline Chili, is opening a flagship location in the Fifth Third headquarters. Skyline CEO Dick Williams said Spence is a friend, and that the bank wanted more dining options as it moved employees back downtown.

Lifelong Texan Peter Sefzik, formerly of Comerica and now head of wealth and asset management for Fifth Third, relocated to Cincinnati several months ago. When friends and colleagues urged him to try Cincinnati chili, he didn't understand what they meant.

He and his family tried Skyline soon after moving. He ordered a "chilito, " which is chili and cheese wrapped in a tortilla (spaghetti and sour cream are optional). He says he loved it. "I can eat a tortilla any time of the day. So, perfect for me."

Spence views the chili debate as a way of bringing together two cultures. As with most merger integrations, layoffs have followed: Fifth Third has cut several hundred positions in Michigan and Texas, and closed some branches in Michigan.

Spence is sketching out the contours of a bank-wide contest, where different regions will nominate their champions to compete in a final round of taste-testing.

Employees across the country will be able to nominate judges. Results will be binding.

Write to Ben Glickman at ben.glickman@wsj.com