The Shariah gives the right to the owner of the property to hire it out for any period of time, be it a small time period or a long one. Thus, making an agreement for hiring out the property for 25 or 50 years is perfectly permissible in light of the Shariah.
As mentioned in Tabyeen Ul Haqaaiq Sharh Kanz ud Daqaaiq, Kitaab Ul Ijaarah.
And Allah Most High knows best.
Mufti Hafidh Syed Ziauddin Naqshbandi Qadri
[Professor, Islamic Law, Jamia Nizamia,
Founder-Director, Abul Hasanaat Islamic Research Center]