A US judge on Tuesday approved a $4.5 billion deal in which BP pleaded guilty to criminal charges from the 2010 Gulf of Mexico oil spill -- but the British energy giant\'s legal woes are far from over. BP is set to return to the New Orleans courthouse on February 25 for a mammoth trial consolidating scores of remaining lawsuits stemming from the worst environmental disaster to strike the United States. It must still resolve a civil case on environmental fines which could amount to as much as $18 billion if gross negligence is found. It also remains on the hook for economic damages, including the cost of environmental rehabilitation. The blowout on the BP-leased Deepwater Horizon drilling rig on April 20, 2010 killed 11 people and sent some 4.9 million barrels of oil into the Gulf, blackening beaches in five states. BP America vice president Luke Keller apologized to the families of the deceased and other victims at a hearing in New Orleans.\"Our guilty plea makes clear, BP understands and acknowledges its role in that tragedy, and we apologize -- BP apologizes -- to all those injured and especially to the families of the lost loved ones,\" Keller said in a statement provided by BP. \"BP is also sorry for the harm to the environment that resulted from the spill, and we apologize to the individuals and communities who were injured.\" It took 87 days to cap BP\'s runaway well 5,000 feet (1,500 meters) below the ocean surface off the coast of Louisiana. BP pleaded guilty in November to 11 counts of manslaughter, one count of felony obstruction of Congress and two environmental violations. It has signaled it will continue to aggressively pursue damages from rig operator Transocean and well operations subcontractor Halliburton, which BP blames for faulty work leading up to the blowout. Judge Carl Barbier -- an expert in maritime law charged with consolidating hundreds of spill-related lawsuits into the single case -- has left the door open to some shared liability in key pre-trial rulings. Several government probes have already castigated BP, Transocean and Halliburton -- which was responsible for the well\'s faulty cement job -- for cutting corners and missing crucial warning signs. Transocean agreed last month to pay a $1.4 billion fine and plead guilty to violating the Clean Water Act, but it argues that, as operator, BP must accept full liability for the disaster.