(Adds quake details and Finance Minister stopping mid-speech)
MEXICO CITY, May 8 (Reuters) - A 6.4 magnitude earthquake shook Mexico City on Thursday, rattling buildings and prompting office evacuations, but there were no immediate reports of damage.
The U.S. Geological Survey put the quake epicenter in the western Mexican state of Guerrero at a depth of 14.9 miles (23.9 km) just inland from the Pacific Coast. No tsunami alert was triggered.
The USGS initially said the quake was of 6.8 magnitude, and had reported it was much shallower. A quake of that magnitude can cause damage to buildings, especially poorly designed structures.
Finance Minister Luis Videgaray was mid-speech at the National Palace in Mexico City when the quake struck.
“I think we’d better take a pause if you don’t mind,” he said, leaving the stage. Onlookers flooded out.
A representative for state oil giant Pemex said they did not believe there was any impact to its installations, the majority of which are located far from the epicenter.
Mexico, Chile and Central America have been rattled by a series of quakes along the Pacific in recent months.
Mexican media reported there was no damage in the Pacific holiday resort of Acapulco, near the epicenter.
“I was working when I started to feel seasick and we left the office,” said Andres Alcocer, 34, a publicist in Mexico City.
A 8.1-magnitude earthquake in 1985 killed thousands of people in Mexico City. In March 2012, there was a 7.4 magnitude quake but it did not cause major damage. (Reporting by Mexico Newsroom; Editing by Chizu Nomiyama and Grant McCool)