( 1. ) THE petitioners were employed as Supervisors (Electrical) in the construction section of the Bhilai Steel Plant when it was a departmental undertaking of the Government of India. Even after taking over of the Plant by the Hindusthan Steel Private Limited, which is a Government Company incorporated under the Companies Act, the petitioners continued in the construction section. In July 1966, both the petitioners were working as Construction Assistants, Grade I, in the pay scale of Rs. 350-575. Both the petitioners were offered employment as Charge men in the grade of Rs. 325-15-475 on the operation side on terms and conditions contained in the managements letter dated 6th July 1966. The petitioners accepted the offer and joined as Charge-men in July 1966. On the date of joining as Charge man, petitioner No. 1 was drawing a basic salary of Rs. 410 per month, while petitioner No. 2 was drawing a basic salary of Rs. 500 per month. During the period of probation as charge men, the petitioners continued to draw the said emoluments but after they completed the period of probation, their basic salary was brought to the minimum of the scale of Rs. 325-15-475. This was done i