SAN FRANCISCO (AP) — A group of city officials, consumer advocates and a state lawmaker on Wednesday attacked California regulators' decision to hire former U.S. Sen. George Mitchell to oversee private settlement talks over a deadly pipeline explosion, calling the process an unfair backroom deal.

The California Public Utilities Commission announced Monday that Mitchell had been appointed to help energy regulators and Pacific Gas & Electric Co. reach a settlement over how much the utility should pay in connection with the San Bruno blast.

Eight people died and 38 homes were destroyed in the gas-fueled inferno that tore through the bedroom community of San Bruno on Sept 9, 2010 after one of PG&E's pipelines ruptured.

Attorneys from the cities of San Bruno and San Francisco, as well as the commission's own consumer advocacy branch, known as the Division of Ratepayer Advocates, said they were not consulted about Mitchell's appointment until days after the commission decided to hire him as a mediator and told PG&E about the decision.

The commission did not immediately respond to questions about how or when the agency hired Mitchell, and the former senator's law firm did not immediately return calls and emails seeking comment.

Commissioner Mike Florio said in an interview he felt the move to inform PG&E first had not been well thought out.

"I think we handled this rather poorly. Announcing it before people were brought into it was not a good idea," Florio said.

Over the past two years, the company has faced grueling public hearings over potential malfeasance leading up to the blast.

One proceeding, chaired by Florio along with commission President Michael Peevey, was intended to determine the level of fines PG&E would face. But a commission judge suspended the hearings last week to instead hold a fresh round of talks between PG&E and other parties.

Peevey said holding closed-door negotiations could lead to a quicker settlement.

Consumer groups said they feared that moving from a public process to private talks chaired by Mitchell would favor PG&E and help the company whittle down possible fines that could reach hundreds of millions of dollars.

"Why not finish the hearings?" said Karen Paull, a lawyer for the Division of Ratepayer Advocates. "Instead, we are being treated like mushrooms ... Feed them manure and keep them in the dark."

In a letter filed Wednesday, the organizations said they don't question the talents of Mitchell — who brokered the 1998 Northern Ireland treaty and spent two years as President Obama's special Middle East envoy — but are concerned that he and his law firm, DLA Piper, previously have represented public utilities.

PG&E declined to comment on the group's concerns but earlier this week praised the news of Mitchell's hiring.

"We are committed to resolving this as quickly and fairly as possible for all parties," said PG&E spokesman Todd Burke. "We've supported negotiations that lead to a universal settlement."

Any decision on fines brokered by Mitchell ultimately will be considered by the full five-member commission.