Does the extension to the pro-completion of a left exact (finite) colimit preserving functor preserve (finite) colimits

Let $\mathbf C$ be a category with finite limits. Then a left exact functor $F\colon \mathbf C\to \mathbf{Set}$ is pro-representable and hence extends to the pro-completion $\mathbf C$. My question is whether it is true that the extension of $F$ preserves finite colimits whenever $F$ does, and if so what is a reference? I'm also curious about arbitrary colimits but for the application I care about, finite colimits (or even coequalizers) are enough.

• what do you mean here by the extension of $F$ to $pro(C)$ the pro-completion of $C$?? $\mathbf{Set}$ has cofiltered limits, so any functor $G \colon C \to \mathbf{Set}$ extends to the pro-completion (this is a free completion) regardless of $F$ being left exact or not. – Eduardo Pareja Tobes Jul 22 '11 at 16:35
• Under my assumptions F is representable on pro(C). I want to know whether this representable functor on pro(C) preserves finite colimits if F did on C. – Benjamin Steinberg Jul 22 '11 at 17:37
• Ok, I see what you mean; just a little clarification: by "this representable functor on $pro(C)$" you mean 1. $pro(C)(-,F)\colon pro(C)^{op} \to \mathbf{Set}$ or 2. $pro(C)(F,-)\colon pro(C) \to \mathbf{Set}$?? – Eduardo Pareja Tobes Jul 24 '11 at 19:13
• The covariant representable, i.e., option 2. – Benjamin Steinberg Jul 25 '11 at 18:27