First Niagara (FNFG) in Buffalo, N.Y. is looking for a permanent chief executive following the abrupt departure of John Koelmel.

The $38 billion-asset company said in a press release late Tuesday that Gary Crosby will serve as its interim CEO, effective immediately. First Niagara said that it reached a mutual agreement with Koelmel to part ways.

The company's board has formed a committee of directors who have no ties to management to search for a permanent successor.

Crosby has been First Niagara's chief administrative and operating officer since joining the company in 2009 from ClientLogic, a firm he helped found. Crosby, who was also a partner at a venture capital firm, had held a series of top posts in banking and manufacturing earlier in his career, First Niagara said in its release.

"Koelmel has guided the company's transformation from a local thrift to a leading northeast banking franchise, and led First Niagara during a period of difficult economic conditions and financial industry turmoil," G. Thomas Bowers, First Niagara's chairman, said in the release.

Koelmel has drawn criticism in the past year for his acquisition of dozens of HSBC branches in New York, and the company's market capitalization and stock price took substantial hits in 2012.

Subscribe Now

Access to authoritative analysis and perspective and our data-driven report series.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.