Pacific Gas and Electric Co. could use state-authorized bonds to settle Wine Country wildfire lawsuits costing billions of dollars, under newly amended legislation in Sacramento.

And those bonds would be paid off by the utility’s customers, prompting critics to label the legislation a “bailout” of PG&E.

The legislation, AB33, would let PG&E use the bond proceeds to settle lawsuit claims for property damage, personal injury and firefighting costs from the series of fires that swept across Northern California in October, destroying 8,880 buildings and killing 45 people. The utility, however, could not use the money to pay any government fines or penalties arising from the fires.

State investigators have so far blamed PG&E’s power lines and equipment for starting 16 of the fires, and more than 200 lawsuits have been filed against the San Francisco company seeking to hold it responsible for the destruction. In 11 of the fires, investigators with the California Department of Forestry and Fire Protection, or Cal Fire, found evidence that PG&E may have broken state safety laws.

PG&E last month announced it would take a $2.5 billion charge against earnings in this year’s second quarter to cover some of the anticipated lawsuit costs. And it warned investors that the company’s full liability could be much larger. Estimates range as high as $15 billion.

“The potential liability from the 2017 northern California wildfires requires immediate legislative action,” reads the bill, from Assemblyman Bill Quirk, D-Hayward. “The number of persons affected by the wildfires, and the extent of their losses, highlight the need for timely and equitable resolution of their claims.”

At the same time, the bill says that the sheer size of PG&E’s potential liability, and the current uncertainty over whether the company would be able to pass those costs on to customers, “create an imminent threat to the utility’s financial stability.” Consumer advocates and some state legislators are adamantly opposed to letting PG&E make its customers pay any costs from the 2017 fires if company negligence played a role in starting the flames.

As a result, the bill will likely face a fight.

Confronted with growing wildfire lawsuit costs, PG&E and the state’s other large utility companies have been lobbying in Sacramento for a change in the state’s liability laws. Gov. Jerry Brown has signaled his interest, announcing last week the formation of a conference committee on ways to “ensure fair allocation of wildfire prevention and response costs in a manner that protects ratepayers.” But insurance companies and lawyers suing PG&E have launched their own lobbying campaigns to block the utilities.

“It’s another backdoor deal for them,” said Erin Brockovich, the legal researcher made famous in the movie of the same name, who is working with several law firms representing fire victims suing PG&E. “It’s inexcusable. I hope the state stops enabling their behavior by giving them passes time and time again.” Brockovich appeared Monday in San Francisco for a news conference opposing the bill.

PG&E welcomed the legislation.

“The measure does not absolve PG&E from responsibility,” said company spokeswoman Lynsey Paulo. “Instead, it takes a balanced, common-sense approach that will protect electric customers, the communities PG&E serves and our state’s clean energy future.”

The bill was introduced by Quirk in 2016 and originally aimed to increase the use of electric cars. Last week, however, it was gutted and amended to address PG&E’s wildfire liability.

Quirk was unavailable for an interview Monday. But his chief of staff, Tomasa Duenas, said the assemblyman wanted to ensure that fire victims would receive prompt compensation, PG&E would not go bankrupt and the company’s customers would not face steep rate hikes.

Under a doctrine known as inverse condemnation, California utilities can be held liable for economic damages from wildfires sparked by their equipment, even if they followed all of the state’s safety rules.

Gov. Brown has insisted that any changes to California’s liability rules would apply only to future fires — not to last fall’s blazes. The newly amended bill, however, specifically addresses the 2017 Northern California fires. It is, in fact, so specific that it appears to apply only to PG&E.

For example, another major utility, Southern California Edison, faces nearly 40 lawsuits from December’s Thomas Fire — the largest blaze in state history. But Edison and the Thomas Fire are not named in the amended legislation, whereas PG&E and the Northern California fires are.

Southern California Edison declined to comment on the bill, other than to say that the company had not yet taken a position on it. Duenas said that Quirk was open to discussing the legislation with other utilities and possibly expanding the language to include them.

The bill would allow PG&E to ask the utilities commission for permission to issue “recovery bonds” to pay for 2017 wildfire costs in excess of the company’s liability insurance. PG&E has roughly $840 million in liability insurance, far less than will likely be needed.

PG&E customers would, over years, pay off the bonds in the form of a non-bypassable charge on their bills. That means even customers who generate most of their own electricity with a rooftop solar array or who buy their electricity from a community choice program such as CleanPowerSF would still pay the charge.

Although the bill does not discuss how large the monthly charge might be, it suggests that the bonds would have less of a financial impact on PG&E customers than other ways of making them pay the wildfire costs.

Still, opponents are furious. “If the Legislature and governor give PG&E a bailout on the fall 2017 fires that they caused and were found negligent in, and at the same time they entertain taking away future victims’ legal rights, where is the incentive for PG&E to act more responsibly in preventing future fires?” said lobbyist Patrick McCallum, who lost his Santa Rosa home in the October fires and now leads the campaign Up From the Ashes.

David R. Baker is a San Francisco Chronicle staff writer. Email: dbaker@sfchronicle.com Twitter: @DavidBakerSF