Feb 6 (Reuters) - Principal Financial Group ( PFG )

reported an increase in fourth-quarter profit on Thursday,

helped by higher premiums and fees in its specialty benefits

business.

The Des Moines, Iowa-based company's premium and fees from

its specialty benefits business, which provides employee benefit

plans to small- and mid-sized businesses, rose 4% to $823.6

million in the quarter ended December 31.

High interest rates have helped insurers rake in more from

fixed-income investments. Their stock portfolios have also seen

a jump, thanks to a rally in equity markets due to economic

resilience and an anticipated business-friendly environment

under President Donald Trump.

The company's adjusted operating earnings were $448.1

million, or $1.94 per share, up from $440.5 million, or $1.83

per share, a year ago.

Its assets under management rose 3% to $712.1 billion.

However, PFG's fourth-quarter net investment income was

marginally down at $1.12 billion, compared with $1.13 billion a

year earlier.