Conservative groups in New Jersey are pushing a proposal that would grant the rights of marriage but not the title to gays, siblings and others involved in domestic partnerships. The plan comes in reaction to a landmark state Supreme Court ruling last month that said gay couples in New Jersey should have access to the same rights and benefits as married couples. Whether to call those rights marriages, civil unions or something else was left up to lawmakers. Under the conservatives’ plan, rights would be available to gay couples, relatives and other twosomes who are not eligible to marry, said Len Deo, president of the New Jersey Family Policy Council. Unrelated opposite-sex couples, who can legally marry, would not be eligible for the designation. For instance, a brother and sister who live together would be able to register under what supporters call an “equal benefits” bill. That way, one sibling could be covered under the other’s employer-sponsored health insurance, and the survivor would not be taxed on inheritance if the other died. Making the law broad would avoid something distasteful to many conservatives elevating the relationships of same-sex couples to the same legal status enjoyed by married couples. Key lawmakers in the Democratic majority in the Legislature say they favor letting gay couples register in civil unions that would offer all the benefits of marriage but not the title. Assembly Speaker Joseph Roberts Jr. has said action may be taken by the end of the year.