Northern Trust reported third-quarter profits of $155.6 million, a 17% decrease from the $187.9 million earned in the third quarter of 2009 and a 22% decrease from the $199.6 million earned in the second quarter of 2010.

Northern Trust also said that custody and fund administration fees increased 6% to $159.2 million, reflecting new business and improved markets.

“Although the economic environment continues to be challenging, we are pleased that assets under custody increased by 10% to $3.9 trillion and assets under management increased 8% to $675.2 billion as compared to a year ago, reflecting continued business growth,” said Frederick H. Waddell, chairman and chief executive officer.