We study deformations of closed string theory by primary fields of con
formal weight (1, 1), using conformal techniques on the complex plane.
A canonical surface integral formalism for computing commutators in a
non-holomorphic theory is constructed, and explicit formulae for defo
rmations of operators are given. We identify the unique regularization
of the arising divergences that respects conformal invariance, and co
nsider the corresponding parallel transport. The associated connection
is metric compatible and carries no curvature.