(Reuters) - Julio Cesar Chavez Jr. was banned nine months and fined $900,000 by the Nevada State Athletic Commission on Thursday for failing a drug test after his loss to Sergio Martinez last September, Top Rank Boxing said.
Chavez, 27, tested positive for marijuana after losing a unanimous decision to Argentina's Martinez in their World Boxing Council middleweight title fight on September 15 in Las Vegas.
The Mexican would regain his active status on June 15, but lawyers for Chavez vowed to appeal what they thought was an excessive fine for what is not considered a performance enhancing drug, said Top Rank, which represents the boxer.
The fine represents 30 percent of Chavez's $3 million purse for the Martinez fight.
The commission's decision took into account a failed doping test in 2009 by Chavez in Las Vegas for a banned diuretic.
Chavez was suspended seven months for that offense, which also resulted in a victory by Chavez over Troy Rowland being changed to a no-decision.
(Reporting by Larry Fine in New York; Editing by Frank Pingue)