NEWARK, N.J. — New Jersey announced a $225 million settlement with Exxon Mobil on Thursday that state officials call the largest environmental settlement against a corporate defendant in state history – although it has been criticized by Democratic lawmakers who say it is a mere fraction of the nearly $9 billion initially sought.

Acting Attorney General John J. Hoffman said the settlement over pollution at refinery sites in Linden and Bayonne is separate from Exxon Mobil’s obligation to clean up the sites at its own expense.

New Jersey filed its lawsuit in 2004, claiming Irving, Texas-based Exxon Mobil’s petroleum refining plants in Linden and Bayonne fouled the land and water. The state sought $8.9 billion in damages.

Several years ago, a state judge ruled Exxon Mobil was liable for causing a public nuisance. A different judge heard evidence last year to determine damages. Attorneys for both sides asked in a letter last month that he refrain from ruling because a settlement was imminent, and on Feb. 20 notified him that a settlement had been reached.