India, Aug. 28 -- Meta Platforms has agreed to pay up to $18 billion to settle claims from nearly every US state that Facebook and Instagram had contributed to a youth mental-health crisis by hooking teenagers on their design, the company and California attorney general Rob Bonta announced in Oakland on Wednesday.

The deal ends a landmark federal trial that had opened only eight days earlier, and closes out the largest coordinated action by state prosecutors against a social-media company to date.

The four states leading the coalition, California, Colorado, Kentucky and New Jersey, had begun opening statements before US district judge Yvonne Gonzalez Rogers on August 18. The settlement was announced the day after Instagram head Adam Mos...