Section 4
SEC. 4. This franchise shall continue for a period of (50) years from the date the said telecommunication services shall be put in actual commercial operations and is made upon the express condition that the same shall be void, unless work of the telecommunication system be begun within two years from the date of the effectivity of this Decree and that system be in operation within four years from said date. Said period may, however, be extended on justifiable grounds by the Secretary of Public Works, Transportation and Communications.