Conformal field theories associated to regular chiral vertex operator algebras, I: Theories over the projective line

Given a chiral vertex operator algebra satisfying a suitable finiteness condition with semisimplicity of the zero-mode algebra as well as a regularity condition for induced modules, we construct conformal field theories over the projective line and prove the factorization theorem. We appropriately generalize the arguments in [TUY] so that we are able to define sheaves of conformal blocks and study them in detail.