The package included up to $7.7 billion in new loans from its foreign bank creditors. The package is the largest ever put together in the international credit markets and the first under the so-called Baker Plan for Third World lending. A Mexican Central Bank official said 434 banks had agreed to participate in the package. Banks were asked to contribute new money in proportion to their outstanding loans to Mexico. The plan by Treasury Secretary James A. Baker III proposed new lending for troubled Third World debtors who enacted policies aimed at encouraging economic growth.