Britain's Cuadrilla pauses gas fracking again following more tremors

LONDON (Reuters) - British shale gas company Cuadrilla has paused fracking at its Preston New Road site in Lancashire, northwest England, for the fourth time since October following a minor seismic event, it said on Friday.

The company has had to repeatedly stop operations at the site since they began two months ago under Britain's traffic light regulation system, which immediately suspends work if seismic activity of magnitude 0.5 or above is detected.

"Cuadrilla has paused and will continue to monitor micro seismicity for at least 18 hours after the event was recorded," the company said in a statement, adding that well integrity "has been checked and verified".

Fracking, or hydraulically fracturing, involves extracting gas from rocks by breaking them up with water and chemicals at high pressure.

It is fiercely opposed by environmentalists who say extracting more fossil fuel is at odds with Britain's commitment to reduce greenhouse gas emissions.

The government however is keen to cut the country's reliance on imports of natural gas, which is used to heat around 80 percent of Britain's homes.

Cuadrilla is 47.4 percent owned by Australia's AJ Lucas, while a fund managed by Riverstone holds a 45.2 percent stake.

Cuadrilla said last month it had extracted its first shale gas from the site. Gas flows were small but coming at such an early stage of the project were evidence of the site's potential, it said.

(Reporting By Susanna Twidale; Editing by David Evans and Jan Harvey)