Judge Consuelo B. Marshall of Federal District Court here accepted the plea from Mr. Riady.
American law bars foreign campaign contributions.
Lippo Group, based in Indonesia, funneled its donations through Hong Kong bank accounts and Lippo entities overseas, the government has said. The judge, Emmet G. Sullivan of United States District Court in Washington, on Thursday rejected motions filed by the coal company, the Peabody Group, and the Southern California Edison Company, a unit of Edison International, that sought to have the case dismissed. The lawsuit by the Navajo Nation, joined by the Hopi Tribe, says that from 1985 to 1987, the companies hired a friend of Donald P. Hodel, the interior secretary, to work with Mr. Hodel on the coal royalties, but did not include the tribes in that process. The negotiations resulted in a 1987 agreement in which the Navajo Nation received a 12.5 percent royalty on coal taken from two strip mines on the Arizona portion of its vast reservation. The interior secretary has trust responsibilities to the Navajo Nation and is supposed to be responsive to its interests.