Members of the US Episcopal Church have rejected a demand from the worldwide Anglican Church that they stop electing gay bishops.
Bishop Gene Robinson is still at the centre of a worldwide row
Correspondents say the decision by the Church's House of Deputies could lead to a permanent split within the world Anglican communion.
The US Church attracted the ire of conservative Anglicans by electing gay bishop Gene Robinson in 2003.
The issue may still be revived before the end of the conference on Wednesday.
The House of Bishops may try to return to the question of a ban but the House of Deputies - which voted against the move by nearly a two-thirds majority - would have to go back on its decision for it to pass.
In Tuesday's vote the House of Deputies - comprising clergy and lay members - rejected a resolution to "refrain from" nominating gay bishops or developing rites for the blessing of same-sex unions.
Two days ago the conference took another radical step by electing a female leader.
Bishop Katharine Jefferts Schori made clear on Monday that she believes homosexuality is not a sin.
BBC religious affairs correspondent Robert Piggott in Columbus, Ohio, says Tuesday's vote was a victory for those at either end of the debate.
While liberals felt the resolution went too far in ruling out an official blessing for same-sex unions and opposing the ordination of gay bishops, traditionalists wanted more restrictions.
The Reverend Susan Russell, the president of liberal group Integrity, insisted: "We have much more in common than we do have difference."
Canon David Anderson of the traditionalist group the American Anglican Council said the vote showed that the Episcopal Church was not prepared to compromise and had "chosen to walk apart" from the rest of the 77-million member Anglican communion.
Katharine Jefferts Schori has made church history with her election
Our correspondent says that, despite the threat of expulsion, the latest developments show how jealously the American Church guards its independence and the level of support for its liberal policy on sexuality.
Earlier on Tuesday the Episcopal convention passed an apology for the ordination of Gene Robinson, as requested by Anglican counterparts, but watered down its reference to "breaching the proper constraints" to "straining the bonds of affection".
Many conservative Anglican churches, especially in Africa and Asia, have already broken ties with the US Church over Gene Robinson's elevation.
The Archbishop of Canterbury, Rowan Williams, the religious head of the Anglican Church, warned that the communion was now facing "exceptionally difficult choices" and has said he fears a permanent rift.