HOUSTON, May 6 - A consortium led by Exxon Mobil ( XOM )

that controls all oil and gas output in Guyana produced 668,000

barrels per day (bpd) of oil last week, the U.S. company's head

for the South American country, Alistair Routledge, said in a

conference on Tuesday.

The group, which is working to install its fourth floating

output facility after receiving it in Guyana's waters in

February, in March produced 627,000 bpd. The 631,000 bpd average

achieved in the first quarter was 3% higher year-on-year, data

from the country's energy ministry showed last month.