An Exxon Mobil consortium's crude output in Guyana has been fully restored at two floating production facilities after workers completed a natural gas pipeline tie-in, a company spokesperson said on Monday.

Output had fallen to between 400,000 and 500,000 barrels per day from July 2 through the end of the month, government data showed, a sign that planned work on the FPSOs had begun.

Oil production was at 669,000 barrels per day as of June 30, the official data showed.

"We safely executed shutdowns of the Liza Unity and Destiny FPSOs to facilitate pipeline tie-ins for the gas-to-energy project," the spokesperson said by email. "Both FPSOs are back online at full production levels."

Exxon said earlier this year it would shut two offshore oil production vessels in Guyana for two weeks each between July and August to connect a natural gas pipeline that would feed planned onshore power plant and gas-processing facilities.

Oil output at one of Exxon's FPSOs was halted from July 2-15, while the second FPSO suspended operations on July 19-31. The consortium's third facility was unaffected, the data showed.

The associated production volumes were deferred, not lost, Exxon said.

The Exxon-led consortium, which includes Hess and CNOOC, is responsible for all production in the South American nation.

(Reuters - Reporting by Kemol King in Georgetown, writing by Marianna Parraga in Houston; Editing by Richard Chang)