British aerospace firm Rolls-Royce is to pull out of Sudan in light of its concerns about the worsening humanitarian situation in Darfur.
The conflict in Darfur has left millions of people displaced
Rolls, which supplies engines to oil firms in the country, said it would "progressively withdraw" from existing contracts and not seek new business.
Foreign firms have come under pressure to cease their Sudanese operations in response to the situation in Darfur.
More than 200,000 people have died during the four-year conflict there.
The UN is set to consider a new resolution to try to end the violence between rebels and the pro-government Arab militia, which has also left more than two million people displaced.
Although it does not have any presence in Darfur, Rolls has been providing support services to oil producers in Sudan for more than five years.
The firm does not have any contracts with the Sudanese government and its business there represents only a small fraction of its global operations.
The decision to gradually remove its 20 staff had been taken "in view of increasing international humanitarian concerns about the situation in Darfur", the firm said.
"The company recently reviewed its position and has decided it should discontinue business in Sudan," it added.
"Rolls-Royce believes this is a responsible line to adopt in the current circumstances."
'Fuelling the crisis'
Critics of the Sudanese government's role in the violence in Darfur and the plight of the people in the region welcomed the firm's decision.
"Companies cannot blinker themselves from the impact they are having on the vulnerable people of Sudan," said Hamish Falconer, from Sudan Divestment UK, a body which campaigns for businesses to sever their commercial links with Sudan.
"It is a stark challenge to the other companies whose operations are helping fuel the world's worst humanitarian crisis."
Sudan remains one of Africa's leading oil producers, with many foreign companies active in the country.