An amendment to define a "single employer" as any two or more business entities engaged primarily in the building and construction industry, performing work within the geographical area covered by a collective bargaining agreement to which any of the entities is a party, performing building or construction work of the type described in such agreement, and having substantial commonality based upon the following four factors: 1) common management; 2) centralized control of labor; 3) interrelation of operations, and 4) common ownership. ? Further, such commonality will be presumed in cases where there are practices of; 1)transfer among the entities of employees performing work described in the collective bargaining agreement; 2) direct competition among the entities in submitting bids for the same work, or 3) deprivation of work by one entity against another.