NEW YORK ( TheStreet) -- TD Ameritrade Holding Corp. ( AMTD) has terminated COO David Kelley, according to a SEC filing. The filing did not say why he was terminated, which will be effective as of Jan 28, 2011. Shares of TD Ameritrade were down nine cents at $20.40. Kelley became COO in 2008, and has worked at Ameritrade since 2006. He previously worked at Merrill Lynch for 19 years before joining Ameritrade, according to Forbes. "Dave has made a significant contribution to TD Ameritrade over the past five years and we wish him well in his future endeavors," said CEO Fred Tomczyk in a press release put out by the company. "He has built a strong technology and operations platform for the company and we are in a good position to transition and increase focus on our front end technology. Dave also built a strong team beneath him, and we are confident they will continue to execute and successfully deliver on our key priorities and objectives." The company told The Wall Street Journal that it is currently searching for a replacement for Kelley. --Written by Maria Woehr in New York. To contact the writer of this article, click here: Maria Woehr. To follow the writer on Twitter, go to http://twitter.com/newsgirlmw. To submit a news tip, send an email to: firstname.lastname@example.org.