  A field theory formulation of two-time physics in d+2 dimensions is obtained
from the covariant quantization of the constraint system associated with the
OSp(n|2) worldline gauge symmetries of two-time physics. Interactions among
fields can then be included consistently with the underlying gauge symmetries.
Through this process a relation between Dirac's work in 1936 on conformal
symmetry in field theory and the more recent worldline formulation of two-time
physics is established while providing a worldline gauge symmetry basis for the
field equations in d+2 dimensions. It is shown that the field theory formalism
goes well beyond Dirac's goal of linearizing conformal symmetry. In accord with
recent results in the worldline approach of two-time physics, the d+2 field
theory can be brought down to diverse d dimensional field theories by solving
the subset of field equations that correspond to the ``kinematic'' constraints.
This process embeds the one ``time'' in d-dimensions in different ways inside
the d+2 dimensional spacetime. Thus, the two-time d+2 field theory appears as a
more fundamental theory from which many one-time d dimensional field theories
are derived. It is suggested that the hidden symmetries and relations among
computed quantities in certain d-dimensional interacting field theories can be
taken as the evidence for the presence of a higher unifying structure in a d+2
dimensional spacetime. These phenomena have similarities with ideas such as
dualities, AdS-CFT correspondence and holography.
