Charter One wanted to sell itself quickly because it feared valuations had peaked, and CenterState was able to beat other potential suitors to the punch.
Nearly a third of the company's revenue will come from noninterest income after it buys SCB, which owns a large insurance and farmland management business.
The Dallas auto lender might lose as much as one-third of its business if it severs ties with the automaker, raising fresh questions about whether its parent company will buy out shareholders and take full ownership.