Brown's deal is worth $47 million, an annual rate of $5.875 million, a source tells ESPN.com's Pierre LeBrun.
The Kings also announced Thursday that Rob Blake has been hired as an assistant general manager for the team with which he starred for 14 seasons as its career leader in goals, assists and points by a defenseman.
Brown has played his entire nine-year NHL career with the Kings, helping them win their first Stanley Cup in 2012. He is the team's only American-born captain, a position he's held since October 2008.
Brown has 181 goals, 207 assists and 452 penalty minutes in 641 regular-season games. He was an All-Star in 2009.
Information from The Associated Press was used in this report.