Project for sales

Dear all

could you help me on the following issue?

i am dealing with a project for sales.

the project has three WBS elements, they are A B and C.

Company I signs the sales contract with the customer.

It subcontracts B and C to its subsidiary company (company II).

when company II finishes B and C, it will sell them to company I.

when company I finishes A, it will sell the finished product to the customers.

I want to know is it possible to achieve the business in PS? and how can I do it?

is it related to intercompany billing? please give me some suggestions and hits.

what else should I pay attention to?

thanks a lot.

Judy