Securian Financial Group said 2017 earnings increased 28 percent to $259 million thanks to "business growth, operating efficiencies, improved mortality rates and strong equity markets that helped its investment management business."

"Every year is unique, but 2017 stands out as a year in which we were able to produce strong financial results while paying the highest amount ever in benefits to our customers," said CEO Christopher Hilger of the St. Paul-based insurer and asset manager in a statement. "In addition, we advanced major efforts to ensure the company's future success."

The company said revenue increased 4 percent to $5.1 billion during the year.

Assets under management increased 11 percent to $78.6 billion, as insurance sales increased 7 percent to $1 billion and insurance in force remained steady at $1.2 trillion.

Annuity sales, including those sold to individuals and retirement plans, increased 29 percent to $2.6 billion. These products generally pay streams of retirement income.

Securian said its insurance and annuity business lines achieved retention results of at least 93 percent, reflecting "the high caliber of service and overall financial value the company delivers."

For the 44th consecutive year, Securian said it would make a profit-sharing contribution to employees' retirement accounts.

The company's contribution for its 2017 results will be 7.7 percent of annual salary. All employees receive the company contribution regardless of whether or what they contribute to their retirement plans.