Equity Zen and Forge Global are often recommended, but are unwilling to help in this case (they are insisting that we go through their secondary market and can't guarantee that I will sell to my specific buyer, they want to get a larger cut of the transaction, etc.). They are also saying that they need my company's CEO's permission as well, which I know isn't true (based on speaking to past employees).
I'm guessing this isn't a commonly advertised service, but there are probably lawyers who are capable of doing this. If anyone can point such a service out to me, that would be greatly appreciated!
When I was at Forge we developed a stock transfer agreement that worked with most any company's setup. I was hoping to post it online and promote it as a universal standard to make everything more efficient, but we had other fish to fry.
The friction is that about half the companies insist on using their own transfer forms and agreements, which are highly company favorable. The companies that let you bring your own documents usually send them to their lawyers for negotiation – and then charge the buyer or seller a transfer fee of a few thousand dollars. Some require a legal opinion vouching for securities law compliance as well, so there's no escaping the lawyers.
My suggestion is that you ask company management if there is a specific stock transfer form they require, and in the alternative whether they can give you a redacted copy of a form they have approved in the past. Failing that, you can ask your friends for the contract they used to sell their own stock.
If the sale price is hundreds of thousands of dollars or more, it's probably worth hiring a lawyer regardless, or going 50/50 with your buyer to hire one together. Per loeber, a fee of a few thousand dollars would be reasonable. If you went with Forge or EquityZen they would end up doing the same legal work in house, plus tacking on their own administrative costs plus profits, which isn't really what they're setup to do. So you can understand the reluctance. But if they can get you a better price, it could be worth it. There are also some private brokers out there, mostly on trades of millions of dollars and up.
Feel free to hit me up for pointers if you get stuck.
This will be a few hours of time for an associate at the firm -- basically to read the existing paperwork you have and then to draft up a transfer agreement. If you're lucky, the forms are all vanilla and they'll have a template on file.
I'd suggest you stay away from the large, white-shoe firms for this -- they will probably be too expensive. I'd use a mid-tier firm, and someone in an office that's not SF/NY. It depends on the firm, but the smaller-city offices tend to be cheaper and still may have a good understanding of securities transfers. You might be able to get someone to do the work in ~10 hours at $300-500/hour. Call a few firms and see if any seems like a fit. First 30min call to explain your situation should usually be free.
Finally, before you start getting the lawyers involved, you may want to contact your company and let them know, since they might be interested in exercising their ROFR. (That would then be a different set of paperwork to review.)