Feb 12 (Reuters) - Principal Financial Group reported a rise in fourth-quarter profit on Monday, thanks to higher premiums and income from investments.

The insurer also said it expects 9% to 12% growth in 2024 adjusted operating earnings per diluted share from a year earlier.

The demand for insurance products typically remains strong in an uncertain economic environment as they are one of the last things businesses and individuals want to cut down on during a slowdown.

Premium and fees from its specialty benefits business, which provides employee benefit plans to small and mid-sized businesses, rose 9% to $791.4 million in the quarter ended Dec. 31.

Higher interest rates have also allowed companies to earn more from investments in assets such as U.S. Treasuries and high-grade bonds.

Fourth-quarter net investment income came in at $1.13 billion, compared with $981.4 million a year earlier, while adjusted operating earnings rose to $440.5 million, or $1.83 per diluted share, from $394.3 million, or $1.58 per share, a year earlier.

The Des Moines, Iowa-based company's assets under management rose 9.3% to $694.5 billion. (Reporting by Arasu Kannagi Basil and Pritam Biswas in Bengaluru; Editing by Shinjini Ganguli)