That special master would gather facts and deliver a report to the court, along with possible recommendations for action.
The entire process could take four months, said states' attorney John Shenefield.
There is little legal precedence to guide Judge Colleen Kollar-Kotelly in making her decision. The closest parallel to the Microsoft case is the 1984 breakup of AT&T by Judge Harold Green, who made a career after the breakup considering the many legal issues and complaints that arose from it.
Kollar-Kotelly heard warnings that the Microsoft case could dominate her time for years to come if she gets the remedy wrong.
Shenefield acknowledged that such a proposal had not been used before in an antitrust case, but added, "There hasn't been an antitrust case like this one either. This is a little unusual."
The special master would have more power then than the three-member "technical committee" that would be set up under the settlement terms reached by the Bush administration, Microsoft and nine of the 18 states originally involved in the case. That committee would consist of a "full-time, on-site compliance team of software design and programming experts, with the means to hire its own staff and consultants, as needed."
This committee would have complete access to Microsoft's records, facilities, systems, equipment and personnel, including source code.
It would also monitor compliance, while providing dispute resolution. If enforcement action is needed, the US "will not have to start from scratch. Rather, it will have the Technical Committee's work product, findings and recommendations to help start any investigation," the government said.
But Microsoft attorney Charles Rule said the states' plan would not make the judge's life easier. He predicted that the special master proposal would have the effect of funnelling more cases to the judge, adding, "the special master provides no firebreak."
Under a plan backed by Microsoft, the US Department of Justice which, Rule said, has much experience in enforcing decrees, could decide what cases to move ahead on.
The two sides are due to reconvene on 19 June for closing arguments, in the case.
The hearings were brought about by the nine states that refused to back the Bush administration settlement with the company. That settlement is also awaiting action by the judge.