European Council says the firms sanctioned are linked to weapons procurement and manufacturing in war-ravaged country.
The six entities were responsible for “supporting activities undermining the stability and political transition of Sudan”, the EC said in a statement on Monday.
Among the companies sanctioned were three controlled by the Sudanese Armed Forces (SAF), including the Defense Industries System conglomerate, which Brussels said had estimated revenues of $2bn in 2020.
The other three companies sanctioned were involved in procuring military equipment for the RSF.
The Sudanese army and the RSF have been fighting since mid-April in a war that has killed more than 12,000 people and which the United Nations says has displaced 7.5 million.
“The entities listed are subject to asset freezes. The provision of funds or economic resources, directly or indirectly, to them or for their benefit is prohibited,” the EC said.
“The EU remains deeply concerned about the humanitarian situation in Sudan and reaffirms its steadfast support for, and solidarity with, the Sudanese people,” it added.
The bloc is mirroring steps taken by the United States, which in June imposed the first sanctions related to the conflict in Sudan by targeting two firms associated with the SAF and the RSF. The UK followed by taking similar measures against businesses linked to Sudanese military groups.
In November, the European Union condemned an escalation of violence in Sudan’s Darfur region, warning of the danger of another genocide after the conflict there between 2003 and 2008 killed some 300,000 people and displaced more than two million.
The fighting has continued to escalate despite international attempts to forge a lasting ceasefire.
On Saturday, Sudan’s government suspended its membership in the Intergovernmental Authority on Development (IGAD), the East African regional bloc that has tried to broker talks between the country’s warring parties.
The conflict broke out over an internationally backed plan to merge the RSF into the army and begin a transition towards elections.
The army and the RSF had shared power after longtime ruler Omar al-Bashir was toppled in a popular uprising in 2019. The two sides had also jointly staged a coup in 2021 that upended efforts to steer Sudan towards democracy.
Throughout the current war, both the army and the RSF have been accused of war crimes, including the indiscriminate shelling of residential areas, torture and arbitrary detention of civilians.