Private equity-backed AssuredPartners Inc. has acquired Amtech Insurance Brokers.

Amtech, headquartered in New York, provides commercial insurance and risk-management services to construction, welding supply and compressed gas businesses. The business has a custom drillers' insurance program for contractors, including water-well, environmental and geothermal drillers.

Lake Mary, Florida-based AssuredPartners is backed by Chicago private equity firm GTCR. The insurance company buys and invests in insurance brokerage businesses in the U.S. and London. The insurer has about 100 offices in 27 states, and two in London. Since 2011, when GTCR invested, the business has acquired more than 80 other insurance agencies.

AssuredPartners' latest transactions include the purchase of Sheehan Insurance Group in December, and Baronsmead Partners, also in December. 

GTCR won Mergers & Acquisitions M&A Mid-Market Private Equity Firm of the Year Award for 2013. The firm partnered with Adams Outdoor Advertising to acquire Fairway Media Group LLC, a billboard group, in January. 

The insurance industry has been consolidating for years. For more, see Insurance Firms Find that Bigger May Be Better.