Ronald Greenspan has a warning for some of the former employees of the now-defunct Brobeck, Phleger & Harrison: A lawyer offering an alternative to a settlement offer based on a contingency fee agreement may end up ripping them off.

In a three-page letter sent Friday, bankruptcy trustee Ronald Greenspan described the motivation of an ad hoc committee formed by some former Brobeck employees to seek options to a settlement offer as “suspect” and motivated by self interest.