Tevez's goals helped West Ham avoid relegation in 2006-07
West Ham will appeal to the Court of Arbitration for Sport over an independent tribunal ruling against them in the Carlos Tevez affair.
The Hammers face having to pay Sheffield United more than �30m in compensation as a result of the ruling.
United claim Tevez was not eligible to play at the end of the 2006/07 season, when he played a key role in West Ham's top flight survival at their expense.
Any decision whether to hold a hearing would be at CAS's discretion.
"While we respect the judgement of the FA arbitration panel, we do not accept that one player's contribution can be placed over that of the team as a whole nor used as the basis for judging the results of a 38-game season," said a West Ham statement.
"This ruling undermines the significant efforts of our entire playing squad and coaching staff over the duration of the 2006/07 Premier League season and does not take sufficient account of the performances of the other 19 clubs in the competition.
"We acknowledge again that the club broke Premier League rules in the original signing of Carlos Tevez but we were dealt with accordingly by an independent Premier League commission and accepted the significant punishment handed down at that time.
"In light of this and the wider implications of this latest ruling for English football we have decided to ask that the case be considered by the Court of Arbitration for Sport."
The Hammers have made the latest move after taking legal advice.
It had been thought that West Ham might be unable to appeal the tribunal's decision, with the Football Association's rule K5c stating that by signing up to arbitration, "the parties shall be deemed to have waived irrevocably any right to appeal, review or any recourse to a court of law".
For clarity, the FA did not sit in judgement on this case, did not have any influence on the decision and did not appoint any of the tribunal members
FA statement
But a leading sports lawyer told BBC Sport: "Rule K5c says you cannot seek redress before a court of law. CAS in not a court of law but a tribunal."
West Ham were found guilty last April of acting improperly and withholding vital documentation over the ownership of Argentine duo Tevez and Javier Mascherano when they signed in 2006.
A three-man Premier League arbitration panel fined the Hammers �5.5m, but did not dock them points, and they went on to survive the drop on the final day, while Sheffield United were relegated.
Having failed in their attempt to have the original punishment overturned, the Yorkshire club invoked a Football Association rule that allows clubs with a legal dispute to go before an independent tribunal.
Sheffield United's claim was considered by former MCC president Lord Griffiths, Sir Anthony Colman, a former High Court judge, and Robert Englehart QC.
West Ham insisted in the statement on Tuesday that the potential outcome of the hearing and compensation they might have to pay had nothing to do with the summer transfers of Anton Ferdinand, George McCartney, Bobby Zamora and John Pantsil.
"With regard to the club's transfer activity this summer, we made no assumptions in terms of the arbitration panel and were only informed of the ruling on Friday," the club said.
"The only considerations taken into account were our previously stated aims of improving the first team with top-quality players.
"We are delighted with the signings made and furthermore the club were able to reject a number of significant bids for first-team players during the summer."
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