Wintrust CEO and President Ed Wehmer is excited about buying Diamond Bank and expanding Wintrust’s Chicagoland presence.

Wintrust Financial Corp. agreed to buy the parent of Diamond Bancorp Inc., which has branches in Chicago, Schaumburg, Elmhurst and Northbrook.

According to The Chicago Tribune, Schuamburg-based Diamond Bank, which has around $165 million in assets, was losing money as of June 30, and its capitol levels have been eroding.

Rosemont-based Wintrust has assets of $18 billion, runs 15 community banks and has 115 branches, mostly in Illinois.

“This transaction provides a great opportunity to expand our presence on the north side of the city of Chicago and to supplement our suburban franchise,” Wintrust CEO and President, Ed Wehmer, said in a statement.

Diamond Bank President Matthew Gambs — who was among the community bankers who met with President Obama early in his first term at the White House — told The Chicago Tribune that he is excited about “the opportunity to combine resources with Wintrust.”

Diamond Bank had the intention of becoming a $500 million-asset banking company, but peaked at about $300 million. In 2011, Gambs told the Tribune that the Diamond job had been tougher than expected.

The deal is expected to close early in the fourth quarter. Terms of the deal, “are not being disclosed at this time,” the companies said in a statement.