"The Movement for the Emancipation of the Niger Delta will intervene towards the release of the two German construction staff of Julius Berger who were ambushed and kidnapped for ransom in Rivers state," the group said in an e-mail to AFP.
MEND said it was making contacts with the abductors who seized the Germans on a construction site in the volatile oil-rich region on July 11.
"MEND has located and identified the culprits and will begin negotiating with the kidnappers in the hope for a safe and unconditional release of the captives," it said.
The group said it took the decision "because the men are involved in construction of infrastructure in the Niger Delta region."
MEND, which claims to be fighting for greater control of the region's oil wealth by local people, came into prominence in January 2006.
It has carried out a series of violent attacks on the oil industry and kidnapped hundreds of local and expatriate workers in the restive region.
Several foreign firms, including French tyre company Michelin and oil servicing firm Wilbros, have left the Niger Delta because of security problems.
The unrest has reduced Nigeria's oil output by a quarter, causing it to lose its position as Africa's biggest oil producer to Angola, according to April figures from the Organisation of Petroleum Exporting Countries (OPEC).