BRUSSELS, August 6, 2008 (AFP) - Six world powers are to confer by telephone at 1115 GMT Wednesday on whether to seek new sanctions or keep talking to Iran after its ambiguous response to an offer to end the dispute over its nuclear programme, a diplomatic source said.

'That's 1:15 pm Brussels time,' the source said, when the five permanent members of the Un security Council plus Germany will hold telephone talks on a letter sent by Tehran on Tuesday which asked for clarification of their offer.