68 P.S. § 250.201. Leases for not more than three years
Real property, including any personal property thereon, may be leased for a term of not more than three years by a landlord or his agent to a tenant or his agent, by oral or written contract or agreement. [Act of April 6, 1951, P.L. 69, art. II, § 201.]

68 P.S. § 250.202. Leases for more than three years
Real property, including any personal property thereon, may be leased for a term of more than three years by a landlord to a tenant or by their respective agents lawfully authorized in writing. Any such lease must be in writing and signed by the parties making or creating the same, otherwise it shall have the force and effect of a lease at will only and shall not be given any greater force or effect either in law or equity, notwithstanding any consideration therefor, unless the tenancy has continued for more than one year and the landlord and tenant have recognized its rightful existence by claiming and admitting liability for the rent, in which case the tenancy shall become one from year to year. [Act of April 6, 1951, P.L. 69, art. II, § 202.]

68 P.S. § 250.203. Assignment, grant and surrender of leases to be in writing; exception
No lease of any real property made or created for a term of more than three years shall be assigned, granted or surrendered except in writing signed by the party assigning, granting or surrendering the same or his agent, unless such assigning, granting or surrendering shall result from operation of law. [Act of April 6, 1951, P.L. 69, art. II, § 203.]