Minneapolis-based Allianz Life Insurance Company of North America posted operating profit of $381 million for the first half of 2012 compared to profit of $315 million during the first six months of 2011. A growing asset base combined with gains realized on investments was the driving force behind the strong profit performance.

Total assets under management reached $99.6 billion, representing 9 percent growth compared to a year ago. Sustained customer balances coupled with positive investment returns generated this growth. New product offerings during the period enhanced Allianz Life's position as the leading provider of fixed index annuities in the United States, according to AnnuitySpecs.com.

Historically low interest rates continue to challenge performance as sales volumes during the first half of the year were mixed. Allianz Life reported premiums of $5.2 billion for the first half of 2012, compared to $5.6 billion in the first half of 2011. Fixed annuity premium of $2.9 billion was down 15 percent year-to-date compared to 2011 and variable annuity premium of $2.0 billion was flat. Sales of life insurance were $31 million, up more than 100 percent year-to-date from 2011.