Mobigame and Connect2Media believe Edge Games has no "enforceable" registered trademark in the UK or the US and that Tim Langdell's company has "misrepresented" what it does own.
"Both Mobigame and Connect2Media have taken extensive legal advice on this issue, and neither company considers that Edge Games has any enforceable registered trademarks in relation to computer game," a statement from the pair, who develop and publish iPhone title Edge - the source of the dispute with Edge Games - began.
"The US and UK trademarks that Edge Games typically refers to when making claims of infringement, are either not yet registered, subject to revocation/opposition proceedings or irrelevant to the field of computer games.
"Of those Edge Games' registered trademarks that are currently subject to revocation/opposition proceedings, the legal advice obtained by Mobigame is that they will almost certainly be revoked or cancelled by the respective trademark offices.
"In view of the above, neither Mobigame nor Connect2Media intend to concede to the demands made by Edge Games, by removing [iPhone game] Edge from sale anywhere in the world, or by changing its name," they added.
The duo said EDGE was one of the "most innovative" titles available in "the mobile domain", and that both parties would "fully defend spurious claims" made by Edge Games, "which we consider to have no legal basis".
"Mobigame and Connect2Media also consider that Edge Games is deliberately misrepresenting the nature and merits of its claims against Mobigame and Connect2Media (and the position in third parties such as Apple) in order to hinder their sales of Edge," the statement concluded.
"Mobigame and Connect2Media consider any such statements to be defamatory, and they may in future claim damages from Edge Games and/or Dr Timothy Langdell in respect of any losses arising from the defamatory statements."
Electronic Arts is currently petitioning to have all of Edge Games' Edge-related trademarks revoked. A spokesperson for Edge Games - possibly Langdell himself - claimed on Friday that the company is "completely certain" of legal victory, not only against EA, but also against Mobigame.