The nature of double- and triple-side agreements in social partnership and their role in the system of the sources of labour law is examined. The points of scope, the obligatoriness and the increase of effectiveness of the agreements is explored. The attention is given to a regulatory technique specific to the agreements - a references. The role of the agreements in regulation of wages relationships and another aspects of labour relationships is analysed. The inference made that the the procedures of wages regulation by means of the agreements is still in the making, and is poorly correlated with economic efficiency indicators. The solutions to a certain problems of legislatory regulation of labour relations are provided, being grounded on the hypothesis of the poor performance of the social partnership machinery in balancing parties' interests. The opportunities of the use of the agreements in filling the gaps, the refinement of the rules of labour legislation are exposed. The conclusion made that the role of the private law regulation tend to increase.