VIENNA - Iran and six big powers began expert-level talks on Wednesday, building on diplomatic momentum created by a pragmatic shift in Tehran towards negotiating a peaceful solution to the dispute over Iranian nuclear ambitions.Highlighting one big hurdle, Iran said it was continuing its most sensitive nuclear activity, uranium enrichment to a level close to that needed for bombs, denying a statement by a parliamentarian last week that it was halted."There has been no stop in the production process," Iranian nuclear energy chief Ali Akbar Salehi told Iranian parliamentary news agency Icana.
