By Ed Harris

ASMARA, Feb 7 (Reuters) - Sudan's eastern rebels said on Tuesday they were postponing indefinitely talks with the government aimed at ending conflict in a region that contains the country's port, main oil pipeline and largest gold mine.

Talks were initially supposed to start in Libya in December but were postponed and now the Eastern Front rebels said they would not take place, accusing Khartoum of preparing for a fresh conflict and denying rebel grievances.

"The Eastern Front declares the postponement of the expected talks in Tripoli to an unspecified date," said a statement issued to journalists in the capital of neighbouring Eritrea, where most of the movement's leadership is based.

The statement accused Khartoum of a "military redeployment during the past few days ... (in) preparation for an assault on camps of the Eastern Front when the leaders and cadres are meant to be in Tripoli negotiating with the government."

Like rebel groups fighting in the western region of Darfur, eastern rebels complain of neglect and marginalisation by the central government in Khartoum.

East Sudan contains Port Sudan, the head of the main pipeline for the country's oil exports, as well as mineral wealth and offshore natural gas reserves.

The postponement will allow the Eastern Front to make the necessary arrangements "to confront the National Congress machinations designed to destroy the cause of the Eastern Front," it added, referring to the government in Khartoum.

The Eastern Front includes both eastern rebel groups and the main political parties in an area impoverished despite its relative economic importance.

Rebels took up arms in the 1990s and control the small Hamesh Koreb area. In January, government-allied forces entered Hamesh Koreb and clashed with rebels in an area that borders Eritrea.

"(In Hamesh Koreb) the government tried to transform the conflict to one between citizens of the same region," the statement said.

Sudan has often armed local tribes as proxy forces to fight regional conflicts because of the toll a long southern civil war took on its regular armed forces. The southern war ended last year with a peace deal but conflict continues in Darfur.