Iran refused to budge Tuesday in opposing the agenda language of a 130-nation nuclear conference, stalling the meeting for its seventh straight day and leading organizers to contemplate ending it prematurely without result. Delegates said Iran had not changed its insistence on changes in the text of the agenda of the conference, which is meant to work on strengthening the Nuclear Nonproliferation Treaty. This appeared to doom the chance that a compromise floated by South Africa would be accepted by consensus - the traditional way of decision-making at such meetings. And this, in turn, the delegates said, could lead the chairman of the gathering to declare its end in failure - or adjourn it until Friday, in a face-saving move, that would allow it to end on schedule but without any substantive work being done. The alternative would be a highly irregular vote, further hardening the fronts and possibly dooming future annual meetings leading up to the 2010 treaty review conference because of insistence by many delegations that consensus decisions are key.