Fidelity Investments’ operating profit rose 17% in 2010 to nearly $3 billion, up from $2.51 billion in 2009, driven by strong mutual fund sales and brokerage business. The company released the information in its annual report to private shareholders.

Revenue rose nearly 7% to $12.3 billion, up from $11.5 billion the year before. And assets under management rose 6% to nearly $1.6 trillion, primarily due to the S&P 500’s 15% gain in 2010. Total assets under administration rose 8% to $3.5 trillion.

Fidelity also limited its expense growth to 4% last year, keeping its workforce steady at 37,000 in 2010. However, it is down 19.5% from a peak of 46,000 in 2007.