The donation was made under an agreement for cooperation between Serbia and the Serb Republic, news provider Indikator quoted the Serb Republic's government as saying on Saturday.
Serbia has announced it would donate about 100 million euro for the construction of the motorway section, according to the media report.
Earlier this year, Autoputevi RS, the state-owned motorway operator of the Serb Republic, said it awarded a 258.2 million marka ($132.3 million/132 million euro) contract for the design and construction of the Bijeljina-Raca section to a consortium comprising local Integral Inzenjering, Institut za Gradevinarstvo (IG) and Serbia's Srbijaautoput.
The 21-kilometre Bijeljina - Raca section is part of a planned motorway that will link Banja Luka, the main city of Bosnia's Serb Republic entity, to Serbian capital Belgrade, thus also connecting Belgrade to the Bosnian capital Sarajevo.
The Serb Republic is one of two autonomous entities that form Bosnia and Herzegovina. The other one is the Federation.
(1 euro = 1.95583 marka)