The Catholic Diocese of Belleville and Catholic Social Services of Southern Illinois said Thursday that they would part ways in the wake of a new state law that granted same-sex couples the right to seek civil unions and disrupted the work of Catholic agencies working in foster care and adoption.

The announcement came in separate statements months after the Illinois Department of Children and Family Services stopped referring foster care and adoption cases to Catholic charitable groups. Catholic agencies have refused to license same-sex couples in civil unions as foster parents, a position the state sees as discriminatory.

The Catholic Charities agency in Rockford, Ill., opted to pull out of the state's foster care and adoption system on its own in response to the Illinois decision.

A statement from the Belleville Diocese said Catholic Social Services of Illinois "chose to disassociate from the Diocese," because it was "unable to remain faithful to the moral teaching of the Catholic Church" while adhering to the new law. The statement said the agency, which directs foster parents over more than 600 children, would "no longer be connected to or sponsored by the Diocese."

The agency, which incorporated in 1947 as Catholic Charities of the Diocese of Belleville and will now be called Christian Social Services of Illinois, said in its statement that it was separating from the Belleville Diocese so it could adhere to the new law. The agency has offices in Belleville, Carbondale, Mount Carmel, Mount Vernon and Olney. Its 630 foster care cases account for much of its $13 million budget.

In a statement, the agency's executive director Gary Huelsmann said that the separation "is best for the children by providing for their continuity of care and allowing for the retention of the caring, dedicated and professional staff employed by the agency."

Illinois oversees the foster care system but contracts 80 percent of the caseload to private agencies, of which many are faith-based. In the past, Catholic agencies referred same-sex couples who wanted to be licensed as foster parents to other agencies. Catholic groups say the new law is impinging on their religious freedom.

In an interview, Huelsmann said none of the agency's 187 employees had resigned over the decision to adhere to the new law, though he conceded "there could be" resignations in the future, though it was "too early to tell."

The Rev. John Myler, rector of St. Peter Cathedral in Belleville, did not comment beyond the diocese's statement, but said a joint statement from Illinois bishops on the topic of the new law "may be forthcoming in the next several days."