Can you buy a house and the seller keep a portion of the land?

[Lakeither Garner]

Greetings Everyone

I'm in the process of buying a investment property that sits on a lot that the owner wants to sell and retain a portion of the land to sale separately. He has already submitted the lot subdivision application and survey to the city of Atlanta for approval.  I spoke with the city and they confirmed that the application was indeed filed and they see no reason the lot couldn't be subdivided  pending the necessary infrastructure was put in such as the sewer tap and sidewalk. The problem is my lender is having a fit saying that the owner can't sell a portion and keep a portion without the lot being subdivided completely first. The real estate agent for the seller says yes you can and that he does it all the time.  The lot that the seller wants to retain has been recorded and has an address but no legal description yet.  My question is can this be done? I intend on buying both lots in the long run and currently have an agreement with the seller to buy the other portion of land in a year. The problem is getting this thing financed with private money in its current state.   Thanks for all information.