US-based Kemper has completed the acquisition of California-based Alliance United Group, for around $70m.
The deal was first announced in December 2014.
Established in 2004, Alliance United distributes automotive insurance exclusively through a network of around 900 producers across nearly 2,000 locations in the US.
Kemper chairman, president and CEO Donald Southwell said: "Alliance United fits nicely within our framework, giving us geographic depth in the fast-growing California nonstandard auto market, a market that we already know and serve well.
"The Alliance United leadership team brings a proven track record of profitable growth in the largest state we serve."
According to Kemper, Alliance United’s full year 2015 direct written premiums will be more than $300m.
The acquired business has extensive presence in Southern California and will complement Kemper’s Northern California base.
Kemper provides an array of products to the individual and business markets, including auto insurance, homeowner insurance, renters insurance, life insurance and health insurance.