The Hartford Financial Services Group Inc. said it has agreed to purchase the holding company of excess lines insurer Maxum Specialty Insurance Group, for $170 million in cash.

Alpharetta, Georgia-based Maxum, which focuses on property/casualty coverage for small to medium-sized businesses, will be managed as a separate unit within Hartford's small commercial business unit, Hartford said Wednesday in a statement. The deal, which is subject to regulatory approvals, is expected to close in the third quarter of 2016, according to the statement.

“Today's acquisition supports The Hartford's strategy to profitably grow our business by investing in the product, underwriting and distribution capabilities that are making us a broader and deeper risk player,” Hartford President Doug Elliot said in the statement.

Maxum CEO Marshall Turner said in the statement, “We are pleased to join an iconic company with a proven ability to adapt and redefine itself to remain relevant to customers and distribution partners. We believe that as part of The Hartford we will have a stronger value proposition and greater opportunities to expand our products and market position.”

Hartford said in its statement Maxum will maintain its brand and limited wholesale distribution model, and all Maxum employees will be offered continued employment. The company will continue to be headquartered in Alpharetta and maintain its regional offices in Palatine, Illinois, and Warminster, Pennsylvania.

Maxum, whose holding company is privately held Minneapolis-based Northern Homelands Co., was founded in 2003. It comprises two insurers, Maxum Indemnity Co., a nonadmitted excess and surplus lines insurer, and its subsidiary, Maxum Casualty Insurance Co., an admitted insurer that was acquired in July 2014.

The group reported $157.5 million in direct premiums written in 2015, and posted a 95.5% combined ratio, according to information released by Hartford. It has total capital and surplus of $114.9 million, and a financial strength rating of A-minus from Oldwick, New Jersey-based A.M. Best Co. Inc.

Its underwriting divisions are casualty brokerage, binding, programs, professional liability, management liability, specialty property and specialty inland marine.