A federal judge who has been presiding over a case filed against Texaco by Indians in Ecuador has a potential conflict of interest, say lawyers for the plaintiffs, who filed a motion on Friday requesting that the judge recuse himself. The suit was filed in 1993 on behalf of thousands of Ecuadoreans who say Texaco’s oil development there led to pollution and dire health problems. In 1997, Judge Jed S. Rakoff dismissed the case, saying it had no basis in American courts, but he was overruled by a federal appeals court that sent the case back to him in October 1998. Since then Rakoff has made no move to either dismiss the case or let it go to trial. The plaintiffs’ lawyers are now pointing out that in September 1998, Rakoff attended an all-expenses-paid seminar on environmental issues at a pricey Montana ranch, sponsored by the Foundation for Research on Economics and the Environment, a conservative group funded largely by donations from corporations, including Texaco. A former chief executive of Texaco was a speaker and guest at the same seminar.