Hub International Ltd. is buying Alexander Insurance Agency, adding to years of consolidation in the insurance sector.

Alexander, headquartered in San Antonio, Texas, is an independent broker of commercial lines insurance for the towing and transportation industries. Terms of the deal were not disclosed. The business will become part of Hub Transportation, Hub's segment that focuses on trucking operations.

Hub, headquartered in Chicago, provides insurance and risk management services. The company is a serial acquirer. Recent deals include MGA Partners Inc., a Canadian insurance company that Hub bought in December, and New Jersey insurance operation Fotek Insurance Agency in November. 

Other insurers are scooping up smaller practices to gain scale. For more on the trend, see Insurance Firms Find that Bigger May Be Better.