The quake hit at about 0500 GMT, about 60 kilometers (40 miles) northwest of the city of Concepcion and at a depth of 17 kilometers, the agency said.
A 5.9-magnitude quake struck in the Pacific off the coast of Chile early Tuesday, the US Geological Survey reported.
There was no immediate word on damage or injuries.
Chile is one of the world’s most earthquake-prone countries.
It sits on the Pacific Ocean’s “Ring of Fire,” a seismically turbulent region where many of Earth’s volcanic eruptions and earthquakes occur.
In 2010, an 8.8-magnitude quake and subsequent tsunami killed more than 500 people.