I hold a home loan in Bank XYZ. They are charging me a home loan interest of 12%. Now if i approach them and ask them that i have a loan in a different bank and would want to transfer to Bank XYZ they charge 10.75%. How come new ones are given at 10.75 and existing at 12%?

I hold a home loan in Bank XYZ. They are charging me a home loan interest of 12%. Now if i approach them and ask them that i have a loan in a different bank and would want to transfer to Bank XYZ they charge 10.75%. How come new ones are given at 10.75 and existing at 12%?