I don't see this exact question here so, let me know if I'm overlooking this.

Participation loans: Can we share the borrower credit report with the participating banks if they request it? Would this violate our privacy policy or does this fall under permissible purposes?

Consumer privacy (Reg P) and permissible purpose (FCRA) are really two different things. Providing the information to a potential purchaser is governed under a proper agreement for the purchasers not to further share the information, you should be OK under Regulation P, like any other vendor. If the participants were going to pull their own credit reports, they would need a permissible purpose under the FCRA. Since they are not engaged directly with the consumer, they would not have one.

Thank you.