SunTrust Bank's wealth management businesses posted a weak first quarter, according to the bank's financial results released Monday.

Revenue from trust and investment management services plunged 35% to $84 million from $130 million in the same period a year ago. Revenue was flat from the previous quarter.

The $46 million year-over-year decline in trust and investment management services was due entirely to foregone revenue resulting from the sale of asset management firm RidgeWorth Capital Management in the second quarter of 2014, the parent of the Atlanta-based bank said in the earnings release.

At the end of the first quarter, the trust and investment management business had $45.8 billion in "managed assets" or assets under management, down 9% year-over-year.

Meanwhile, the retail brokerage business, which has enjoyed remarkable growth rates for the past year, slowed in the first quarter. Retail investment services generated $72 million in first-quarter revenue, up 1% year-over-year but down 1% from the previous quarter.

At the end of the first quarter, the bank had $48.4 billion in brokerage assets, up 9% from $44.4 billion in the same quarter of 2014. 

Overall, the company earned $411 million, or 78 cents per average common share, in the first quarter, representing a 7% per share increase year-over-year.

"Continued expense discipline and strong asset quality performance, coupled with growth in noninterest income, contributed to solid performance in the first quarter and helped to mitigate the impact of the persistent low rate environment," William H. Rogers, Jr., chairman and CEO of SunTrust Banks, said in a statement.

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