Are there any participant notice requirements for a plan spin off not involving a termination (other than IRS Form 5310-A). I have a situation where a company is spinning off a division and a portion of the plan assets of the original company's plan are going to a newly established plan to be maintained by the spun off division.

Depends, will there be black out, is new plan safe harbor, use autoenrollment or any other feature that requries notices? We have spun off a number of groups to new or existing plans over the years. We notify them of each step in the process, especially if it involves mapping of funds to new funds. The 404c issues and all that are the reason. Doesn't hurt to ensure all participants are aware of all aspects of the transition.