Prohibited Transactions/Parties in Interest

[MBCarey]

The CEO (the CEO is not an owner) of a manufacturing firm (Company A) decides to move the plan to a new broker and TPA (Company B). The equity owner of Company A is not involved with the day to day management of the Company A, nor is he a plan trustee or administrator nor is involved in the decision to move the plan. After doing some research it is found that the owner of Company A has an investment in a venture fund (Company C)that has invested in the TPA firm (Company B). This investment is with Company C and the investor has no control over what the venture capital (Company C) can invest in or any managment control over any of the companies that Company C invests the venture capital in. Would this be consider a Prohibited Transaction or Arms Length Transaction? Is Company B considered a party in interest?