( 1 ) THE award has a chequered past and since it is necessary for appreciating the dispute in the right perspective to relive it, let me do it first.

( 2 ) ON March 4, 1971 the petitioner-company entered into a Rate Contract with the Union of India through the Director General of Supplies and Disposals, New Delhi. The petitioner was to supply spare parts for the "terex" make of earthmoving and construction equipments for the period from February 17, 1971 to February 16, 1974. However, disputes arose between the parties and consequently an arbitrator was appointed who by his award of July 29, 1977 dismissed the petitioner s claim. Not satisfied, the petitioner filed objections. One of the main objections revolved around clauses l (c) (ii) and l (e) of the Terms and Conditions regarding Custom Duty. Since that objection is still a live-wire, let me first reproduce the said clauses. They are as under:

"1 (C) (II) If during the currency of the rate contract the customs authorities revise the procedure of assessment of customs duty and issue fresh assessment orders indicating percentage of loading to be added to net C. I. F value for calculating the amount of customs du