Brown's attorney, Pat Harris, says he will appeal the decision, arguing that his client has served double what he would face if he was convicted of involuntary manslaughter.
Prosecutors say Brown, a former airport baggage handler, threw Lauren Sarene Key into the Ocean in Rancho Palos Verdes, on November 8, 2000, to avoid paying about $1,000 in monthly child support, and to retaliate against the girl's mother.
Harris argues the girl slipped and fell 120 feet from Inspiration Point. Brown was tried in 2006 and 2009, but juries in both trials deadlocked. In the first trial, in Torrance Superior Court, eight jurors favored a second-degree murder conviction, two wanted first-degree murder, while two argued for involuntary manslaughter.
In Brown's second trial, six jurors voted in favor of convicting Brown of second-degree murder, while the other half favored involuntary manslaughter.
The murder charge against Brown includes the special circumstance allegations of murder for financial gain and murder while lying in wait, which, if convicted, could make him eligible for a life prison sentence without the possibility of parole.
Brown, who has been behind bars since his Nov. 16, 2003 arrest, is due back in court March 2.
The Associated Press contributed to this report.