Where to find a loan with no down payment (but 20% seller carry)

[Daniel Karbownik]

I have found a great deal off market where the seller is willing to carry back 20-30% of the mortgage - I only need to find a bank loan that is willing to loan the other 70-80%.  

My problem is that the first couple lenders that I've spoken to say that fannie and freddie won't take loans where there was a seller carry back and no down payment from the buyer.  It's seeming like it would have to be a portfolio lender who's willing to accept it.  

I've spoken to a couple who have said it's too aggressive for them.