WRAPUP 1-U.S. keeps Sudan sanctions but offers dialogue

* U.S. seeks concrete progress on Darfur, southern Sudan

* Khartoum says new policy has "positive points"

* Rights groups say lack of detailed benchmarks a concern

By Andrew Quinn

WASHINGTON, Oct 19 (Reuters) - The Obama administration on Monday said it would renew economic sanctions on Sudan, but also offered Khartoum new incentives to end violence in Darfur and the semi-autonomous South ahead of polls next year.

President Barack Obama, who during last year's U.S. presidential campaign urged a tougher line on Khartoum, said the action was necessary to prevent the oil-rich African giant from falling further into chaos.

"If the government of Sudan acts to improve the situation on the ground and to advance peace, there will be incentives; if it does not, then there will be increased pressure imposed by the United States and the international community," Obama said in a statement, repeating accusations that the violence in Darfur amounted to genocide.

Sudan's government welcomed the new U.S. approach, which it said exemplified "the new Obama spirit."

"This is a strategy of engagement. It is not a strategy of isolation," Sudanese presidential adviser Ghazi Salahadin told a news conference. "Compared to the previous policies, there are positive points."