Not sure about that, SD. I know Icahn made a statement accepting, but I don't think he was offered the job yet.
But if you have a link, I sure would like it.
http://money.cnn.com/2015/08/07/investing/donald-trump-2016-carl-icahn/index.html
It is confusing to read. Basically Icahn says Trump offered him a position Icahn refused, then later told Trump he accepted the Sec of Treasury position.