And so it begins:

The chairman and chief executive of General Motors, Rick Wagoner, is resigning, just hours before President Obama was expected to unveil his rescue plans for G.M. and the ailing American auto industry, a person close to the decision said Sunday.

Mr. Wagoner was asked to step down as part of G.M.’s restructuring agreement with the Obama administration, according to an administration official who spoke on condition of anonymity because a formal announcement has not been made yet. Mr. Wagoner then agreed to resign.The unexpected move by Mr. Wagoner, who has been at the helm of G.M. for eight years, was not confirmed by the company. A statement about Mr. Wagoner’s future will be issued after the president’s comments, which is expected to be Monday morning.