Serena Williams argues a call with a lines-woman. Williams was fined $10,000 US and could face more punishment. ((Darron Cummings/Associated Press))

Serena Williams has issued a second statement to "sincerely apologize" for her "inappropriate outburst" at the U.S. Open.

A day after she was short on contrition, Williams issued a second statement about a half-hour before she and her sister played in the women's doubles final, more than 36 hours after the 11-time Grand Slam singles champion's profanity-laced tirade at a line official.

The official, a woman, called a foot fault late in Williams's 6-4, 7-5 semifinal loss to eventual singles champion Kim Clijsters on Saturday night.   

"I want to sincerely apologize FIRST to the line official, Kim Clijsters, the USTA and mostly tennis fans everywhere for my inappropriate outburst," Monday's statement read.

"I'm a woman of great pride, faith and integrity, and I admit when I'm wrong," it continued. "I need to make it clear to all young people that I handled myself inappropriately and it's not the way to act — win or lose, good call or bad call in any sport, in any manner. I like to lead by example. We all learn from experiences both good and bad. I will learn and grow from this, and be a better person as a result."   

Williams was fined $10,000 US Sunday for unsportsmanlike conduct and could face further penalties for what U.S. Open tournament director Jim Curley called her "threatening manner."