In a ruling released Monday, Grand Slam administrator Bill Babcock said Williams faces a "probationary period" at tennis' four major championships in 2010 and 2011. If she has another "major offense" at a Grand Slam tournament in that time, the fine would increase to $175,000 and she would be barred from the following U.S. Open.
"But if she does not have another offense in the next two years, the suspension is lifted," Babcock said in a telephone interview from London.
He said Williams is handing over $82,500 right now, already nearly double the previous highest fine for a Grand Slam offense — about $48,000 Jeff Tarango was docked in the 1990s.
Williams lashed out at a lineswoman after a foot-fault call at the end of her semifinal loss to eventual champion Kim Clijsters at the U.S. Open in September.
Williams earned $350,000 by reaching the semifinals, part of her more than $6.5 million in prize money in 2009, a single-season record for women's tennis. Her career prize money tops $28 million.
The American is an 11-time Grand Slam singles champion and ended the 2009 season at No. 1 in the WTA rankings.
Williams' profanity-laced, finger-pointing outburst drew a $10,000 fine from the U.S. Tennis Association in September — the maximum onsite penalty a tennis player can face. But because it happened at a Grand Slam tournament, Babcock was charged with investigating whether further punishment was merited.
He concluded that Williams violated the "major offense" rule for "aggravated behavior." The Grand Slam committee — with one representative from each of the sport's four major championships — approved his decision Saturday.
Babcock said Williams has been informed of the ruling. She has been in Barbados for an exhibition tournament, and her agent did not immediately reply to a request for comment Monday.
The USTA said it would comment later Monday.
Babcock said a "major offense" under Grand Slam rules is "any conduct that is determined to be the 'major offense' of 'aggravated behavior' or 'conduct detrimental to the game.'" There is no specific definition of what sort of actions constitute a "major offense."
He said the highest possible fine that Williams could face — $175,000, if she violates her Grand Slam probation — was chosen because it is the difference in winnings between reaching the quarterfinals and semifinals at the U.S. Open. The $10,000 Williams already was docked by the USTA will be counted toward that total; that's why she is paying half of $165,000 now.
During the Sept. 12 match at Flushing Meadows, the foot fault — a call rarely, if ever, made at that stage of such a significant match — resulted in a double-fault for Williams, moving Clijsters one point from victory.
Williams paused, retrieved a ball to serve again and then stopped. She stepped toward the official, screaming, cursing and shaking the ball at her. Williams was penalized a point for that display; because it happened to come on match point, it ended the semifinal with Clijsters ahead 6-4, 7-5.