Four years after Vietnam veterans settled a lawsuit against manufacturers of the herbicide Agent Orange, a federal judge has set into motion the distribution of $240 million to be used for disability payments and other assistance.

U.S. District Judge Jack B. Weinstein of Brooklyn announced plans Tuesday for handing out the settlement money, which was freed after the U.S. Supreme Court last week removed the last legal obstacle in the lengthy Agent Orange litigation.Cash payments and other benefits could be available early next year, according to the distribution agreement.

The class action, initiated in 1978, was settled in 1984 when seven chemical companies that manufactured Agent Orange agreed to pay $180 million. The settlement has grown to $240 million through interest during the appeals process.

The distribution plan has two major components: a $170 million program to provide cash benefits to long-term, totally disabled veterans and to the families of veterans whose deaths were believed to have been linked to Agent Orange; and a $52 million program to fund social service projects that benefit veterans and their families.