Selling a share in a property at a higher price

I had 2 clients, client A, who wished to buy a property. The client had an agreement with the seller to purchase a property being sold for R900 000. Client A wanted to get bank finance for the shortfall on the purchase price. We advised against it. We spoke to client B, who had R100 000 to invest. We brought both the parties together. Client B agreed to buy 1/9 of the property. Within a month client B agreed to sell his share at R120 000, an agreed of repayment was made and met.

Is the transaction a valid shariah agreement.