I cannot tell without a review of all the documentation. Non-competition agreements are certainly legal in Michigan, and one of the reasons for them is to keep companies which had previously been contracting outside company's employees from converting those jobs to full-time, inside positions, and stripping the contracting company of its employees by hiring them. Obviously, assuming that the contracting company was making money with the placement, that is competitive and detrimental to the contract employee's previous company. On the other hand, I would be surprised that company B was not constrained, and in fact prohibited, from hiring previous contract employees for at least a period of time or without providing some form of consideration to company A. That is normally how contract employee providing the company protects itself.
Answered on Apr 16th, 2014 at 6:37 PM