Large banks are preparing to pay $1.865 billion to settle accusations that they conspired unfairly to control a derivatives market that stood at the center of the financial crisis, a lawyer suing the banks said in court on Friday.

The banks have faced public criticism since the financial crisis for the opaque manner in which their traders bought and sold credit default swaps, a type of financial contract that allows investors to speculate and hedge against losses and that figured prominently in the crisis.

Lawyers for several large investors, including a Los Angeles pension fund, argued in a suit filed in 2013 that the 12 banks — essentially all the largest ones in the world — conspired to keep competitors out of the market, allowing the banks to charge higher prices.

In a hearing on the suit in federal court in Manhattan on Friday morning, a lawyer for the investors suing the banks said they were expecting to complete their settlement with the banks, after months of negotiations, in the next two weeks.