* U.S. envoy says some differences being bridged * Says vote on southern secession must not be delayed * Gration to return to Sudan in September for more talks By Skye Wheeler KHARTOUM, Aug 21 (Reuters) - The U.S. special envoy to Sudan said on Friday some north-south differences that have threatened a fragile 2005 peace deal were gradually being bridged but said nothing should delay a 2011 referendum on southern secession. Scott Gration also told Reuters, speaking after a trip to Sudan, that he would return in September for further talks between the former southern rebel Sudan People's Liberation Movement and the northern-based National Congress Party. Gration oversaw a new agreement between north and south this week for the implementation of a range of disputed elements of the 2005 peace deal, such as the demarcation of both the north-south border and of the oil-producing Abyei area. But other differences remain, including a row over a census, crucial to preparing for elections in 2010 and the referendum. The south says the census result gives population figures that are too low for the south and inflated in the north. "Both sides understand the importance of the elections, understand the importance of having the referendum, and the census in many ways ties into all of this and I believe there's a solution that's going to be here soon," Gration said, speaking by telephone from from Addis Ababa. "I believe that the referendum has to happen on time," he added. He also said the parties were working on the issue of sharing out Sudan's oil wealth, a factor that inflamed the two-decade long war between the mainly Christian and animist south and the largely Muslim north. "The oil wealth is something we're already working through . I think that's something that will be divided fairly and equally," Gration said. Most of Sudan's oil is from southern oil fields, but pipelines and other infrastructure lie in the north. North-south fighting in the Abyei area last year led to dozens of deaths and 50,000 people fled their homes. The United States helped mediate the north-south accord but still has sanctions on Sudan, some in place due to a separate conflict in the western Darfur region. This restricts aid. Gration reiterated that some sanctions should be amended that prevent the United States from sending heavy machinery and other equipment to develop the south before the referendum. "There are certain sanctions right now that inhibit our ability to have effective humanitarian assistance," he said. "Right now we're looking for relief on those sanctions that hurt the very people we're trying to help." (Editing by Edmund Blair)
A woman reacts as she waits outside a morgue in Baghdad, August 20, 2009. A series of blasts in Baghdad killed 95 people and wounded 536 in Iraq's bloodiest day this ...
