Requiring outside contractors to provide affordable healthcare coverage to all employees.
Without the amendment, the corporation could not require prime contractors to employ minority businesses.
The governor also vetoed three bills on Wednesday, including one that would have required contractors to post the prevailing wage rates.
The law, in an effort to create jobs, requires separate contractors for each phase of a construction project.
The Council approved a bill requiring contractors to increase the pay of 3,500 workers.
Would have required contractors to pay "prevailing" wages - union rates - on private projects awarded public money.
The companies also are banned from requiring wholesalers and contractors to use their services exclusively.
The law would require such contractors to have home-improvement licenses.
Various municipalities, however, do require contractors working within their boundaries to be registered with the town.
In turn, companies require their suppliers and contractors to prove that they, too, are Y2K-compliant.