NEW YORK — In its final days, the Obama administration has expanded the power of the National Security Agency to share globally intercepted personal communications with the government’s 16 other intelligence agencies before applying privacy protections.

The new rules significantly relax longstanding limits on what the NSA may do with the information gathered by its most powerful surveillance operations, which are largely unregulated by US wiretapping laws. These include collecting satellite transmissions, phone calls, and e-mails that cross network switches abroad, and messages between people abroad that cross domestic network switches.

The change means that far more officials will be searching raw data. Essentially, the government is reducing the risk that the NSA will fail to recognize that information would be valuable to another agency, but increasing the risk that officials will see private information about innocent people.

Attorney General Loretta E. Lynch signed the new rules on Jan. 3, after the director of national intelligence, James R. Clapper Jr., signed them on Dec. 15, according to a 23-page, largely declassified copy of the procedures.

Patrick Toomey, a lawyer for the American Civil Liberties Union, called the move an erosion of rules intended to protect the privacy of Americans when their messages are caught by the NSA’s powerful global collection methods.

He noted that domestic Internet data was often routed or stored abroad, where it may get vacuumed up without court oversight.