A person familiar with the Justice Department's decision told The Associated Press the agency will not charge the officers. The person was not authorized to talk publicly about the decision and spoke to the AP on condition of anonymity.
The governor's office said the decision will be announced officially on Wednesday, but did not know the exact time.
Alton Sterling was shot and killed during a struggle with the two officers in July.
But the Justice Department's decision not to charge the officers may not be the final legal chapter in the case: The department's decision doesn't preclude state authorities from conducting their own investigation of Alton Sterling's fatal shooting last summer and pursuing their own criminal charges in the case.
Dozens of people meanwhile gathered Tuesday outside the store where Sterling was shot and killed during a struggle with the two officers in July. They held hands and prayed before urging state authorities to take action.