A Pacific Gas & Electric lineman cuts a downed power line during the Camp Fire in Paradise, California, U.S. November 8, 2018. REUTERS/Stephen Lam

(Reuters) - Shares of utility PG&E Corp PCG.N fell 18 percent on Wednesday after the company warned of liquidity concerns if its equipment was found responsible for starting the Camp wildfire currently raging in California.

The company said liabilities related to the wildfires could exceed its recently renewed insurance cover, adding to the severe financial pressure it is already facing.

The utility has already withdrawn $3 billion from its credit line in anticipation of fire-related liabilities, leaving it with no additional money available under its credit agreements, it said in a filing.

The Camp wildfire, which has killed nearly 48 people, is being investigated, and PG&E told regulators it experienced problems with transmission lines or substations in areas around the time the blazes were reported to have started.

NBC said in a report nbcnews.to/2K4tvNZ on Tuesday that a day before the fire started, PG&E emailed a local landowner about "problems with sparks" and the need for workers to enter her property and work on the high-power lines. The company, however, was unable to address the issue as the landowner was out of town, the report said.

The company said in the filing it had renewed liability insurance coverage for wildfire events of about $1.4 billion for the period from Aug. 1 through July 31, 2019.

PG&E did not immediately respond to requests for comment.

The company already faces billions of dollars in potential payouts from lawsuits after California said PG&E’s power lines were responsible for sparking last year’s wildfires.