Rollover 401k to fund Real Estate business

[Mimi Booker]

I've read through the other solo 401k threads but so far I haven't found an answer to my situation.

I have a current 401k plan through my full-time employer.  I also have a small business on the side as a sole proprietor.  Can I rollover the 401k with my current employer to a solo 401k that I start with my business?  Or can you only rollover from a 401k from a previous employer?  

Thanks to everyone who replied to my earlier question about repair costs.