The Romanian and American authorities have renegotiated their contract with US-based Bechtel for the construction of the Transylvania motorway.
Under the renegotiated deal, Bechtel will build about 115km of the 400km highway, which will stretch from central Romania to the Hungarian border.
The new deal, which ends a stand-off over costs and the pace of work, will help Romania save about $8.58bn.
Under the agreement the remaining stretch of the highway will be awarded to other companies.
The agreement was signed in 2004 to build the entire highway, but only 54km was constructed due to cost escalation.