World No. 1 superstar Serena Williams has been fined a record $82,500 and placed on a two-year Grand Slam probation for her September outburst at the U.S. Open.

Williams could be suspended from the U.S. Open if she has another "major offense" at any Grand Slam event over the next two years, in a ruling announced by Grand Slam administrator Bill Babcock on Monday.

If Williams commits another "major offense" at a Grand Slam event over the next two years, her fine would balloon to $175,000 and she would be barred from the following U.S. Open.

A Grand Slam committee, which featured one representative from each of the four major tournaments, approved of the ruling over the weekend.

"On 9 November 2009, the Grand Slam Committee administrator determined Serena Williams had committed the Grand Slam major offence of aggravated behavior for her misconduct at the 2009 U.S. Open," the committee said in a statement.

Williams verbally assaulted a lineswoman during a semifinal match against eventual U.S. Open champion Kim Clijsters in September and wound up losing the bout when a penalty point ended the contest.

The American was serving at 15-30, with Clijsters leading 6-4, 6-5 and one game away from a trip to the final, when a foot fault was called to produce a double fault, making the score 15-40. Clijsters then went on to take the game, set and match when Williams was hit with a penalty point from the chair umpire after the powerful star went into a profanity-laced, finger-pointing tirade at the lineswoman who made the untimely call.

Williams was fined $10,000 by the United States Tennis Association back in September.

The 11-time major champion Williams set a new single-season record on the WTA Tour by earning more than $6.5 million in prize money this year, and the American great also holds the all-time prize money record among the ladies, with over $28.5 million earned.

Williams completed her 2009 campaign earlier this month by going 5-0 at the season-ending Sony Ericsson Championships, where she beat her older sister Venus twice, including a straight-set decision in the finale.

The 27-year-old Williams' 2009 season also included Grand Slam titles at the Australian Open and Wimbledon.

The previous record for a tennis fine was $48,000, which was slapped on another American, Jeff Tarango, in the mid 1990s. Tarango walked off the court during a match at Wimbledon in 1995 and launched a verbal attack at chair umpire Bruno Rebeuh, accusing him of being corrupt.

Tarango was banned from the playing at the following year's Wimbledon.