LPL Financial announced Wednesday that more conservative investor activity led to lower third-quarter profits.

Third-quarter profit totaled $34.3 million, down $2.1 million from $36.4 million last year, LPL said. LPL's adjusted earnings of $53 million, or 47 cents a share, topped estimates by 3 cents per share, according to

Profits were hurt by lower advisor productivity, LPL chief Mark Casady said. “With the backdrop of an uncertain economic environment, individual investors continued to take a cautious approach to engaging with the markets, which led to the subdued levels of advisor productivity we experienced this quarter,” Casady said.

LPL, which took the No. 1 spot in the 2012 Financial Planning survey of the nation's biggest independent broker-dealers, also announced sharp year-over-year growth in both the number of advisors and assets under management. The company added 495 net new advisors. And total advisory and brokerage assets were $371.4 billion at the end of the third quarter, up 17.4% from $316.4 billion as of Sept. 30, 2011. That number was likely boosted by strong market gains; the S&P 500 increased almost 27% over the same period.

Net new advisory assets, which exclude market movement, were $2.9 billion in the third quarter -- representing annualized growth of 9.8%, the company said.

Revenue grew far more slowly, though. Third-quarter net revenue rose 2.8% to $907.2 million from $882.9 million in 2011. "The continued shift of advisors to the independent RIA platform and a re-pricing in one of the company's significant custom clearing agreements have caused the rate of revenue growth to diverge from the rate of advisory asset growth," the company said in its earnings release.

LPL had been expected to report results on Monday, but delayed the release until Wednesday because of Hurricane Sandy.