A New Jersey judge has ruled that Congoleum Corp.’s insurance carriers don’t have to fund a $500 million settlement with the company’s asbestos claimants because it was a bad-faith deal engineered by lawyers acting collusively.

The settlement had been the centerpiece of a prepackaged Chapter 11 petition designed to protect the Mercerville, N.J., floor-products company from claims arising from its use of asbestos before 1983.