* Adam seeks to rally support among minority investors
* Questions whether Dongfeng, state and family in agreement
* Voices concern on remaining shareholders' compensation (Recasts with comments from head of Adam shareholders' group, context)
By Natalie Huet
PARIS, Feb 4 (Reuters) - A French shareholder lobby group is trying to rally support to challenge the terms of a rescue plan for PSA Peugeot Citroen, saying the current proposal will leave the carmaker at the mercy of competing interests.
Adam, which has fought to defend minority investors in major French deals for around 20 years, has written to Peugeot's chairman to express its concerns over a planned 3 billion euro ($4.06 billion) share sale that will leave the company with three big shareholders - the Peugeot family, China's Dongfeng and the French government.
In the letter, made public by French newspaper Les Echos and seen by Reuters, Adam questions whether a "three-headed lion" could agree on a strategic direction for the carmaker.
It also voices concern over how the remaining shareholders will be compensated for the dilutive impact of the share sale.
If Adam wins broader support, it could pose another stumbling block to the plan to rescue Peugeot, which already appears to have divided the company's founding family. Thierry Peugeot has reportedly written to his cousin Robert Peugeot, head of the FFP family holding, to criticise the current plan, which would reduce the family's influence.
Loss-making Peugeot is battling to secure the money it needs to invest in new models and expand abroad in order to reduce its exposure to sluggish European markets.
The Peugeot clan currently controls the carmaker through a 25 percent stake commanding 38 percent of voting rights. The remaining 75 percent of capital is held by funds and private investors, among which Adam hopes to find supporters.
Adam currently represents only a few shareholders. But its president, Colette Neuville, told Reuters it was aiming to win the support of enough investors to block and ultimately renegotiate the terms of the planned capital hike when it is put to vote at a shareholder meeting in the coming months.
To be approved, the capital hike would need the support of about two thirds of voting investors.
"We will not be forced into a solution that does not respect shareholder equality and that does not clearly state what the company's strategic plan is and who is backing it," Neuville said.
Adam argues that under French market rules, if the Peugeot family, Dongfeng and the French state have agreed on a plan for Peugeot, they should launch a formal takeover offer for the company, triggering an offer to buy out minority stockholders.
If they haven't agreed on such a plan, then that should be a source of concern for Peugeot and all of its shareholders.
"Peugeot certainly needs to bring money into its coffers. But what it really needs is a project that will find support over the long run among shareholders who agree on the strategy," Neuville said.
Peugeot declined to comment.
($1 = 0.7397 euros) (Additional reporting by Lionel Laurent and Jean-Michel Belot; Editing by Mark Potter)