( 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 duty, you will intimate the same to this office and the conversion factor will be reworked out accordingly on the basis of revised rate of customs duty thus arriva OPO This new conversion factor will come into effect 12 weeks after the date of announcement of revised procedure of assessment by customs authorities. However, against the supplies made during these 12 weeks, while preferring bills you will furnish a certificate of your internal auditor/accountant to the effect that the items billed for are from stores on which customs duty has been paid by you on the old rates. The stipulation made in clause l (e) will not however be applicable in this case while working out the revised conversion factor. "

"1 (E) ELEMENT OF MARK UP AND MISCELLANEOUS CHARGES The elements of misc. charges and Mark Up allowed in the conversion factor will not be subject to revision upward or downward as the case may be in the event of any variation in exchange rate and/or customs duty, during the three (3) years currency of the Rate Contract. "

( 3 ) THE underlined portion of Clause l (c) (ii) makes it clear that clause l (e) of the Terms and Conditions stood deleted and consequently clause l (e) was not applicable to the instant contract. However, on May 25, 1971 the respondent wrote a letter to the petitioner making certain amendments in the Contract dated March 4,1971 and one of them related to the deletion of the lines underlined by me in clause l (e) (ii) thereby making clause l (e) applicable to the Rate Contract. What, however, is of significance is that the petitioner in its letters dated July 8, 1969 and March 18, 1970 had specifically stated that no unilateral amendment would be made but this is precisely what was done by the Union of India by its letter dated May 25, 1971. Not that the petitioner sat over it. By its letter dated June 21, 1971 it informed the respondent that the amendment leading to the deletion of the sentence in question from Clause l (c) (ii) was not acceptable. This was followed by a notice dated October 6, 1975 to the Director General of Supplies and Disposal complaining about the unilateral deletion and requesting for referring the dispute to arbitration in terms of Clause 18a of the Rate Contract read with clause 24 of the General Conditions of Contract Form No. DG S and D-68 (Revised ). This ultimately led to the appointment of Dr. Bakshish Singh as the sole arbitrator who made and published the award on July 29, 1977. Consequent upon the making of the award, the petitioner filed objections. The main objections were that the arbitrator had not allowed the petitioner to produce a letter dated February 23, 1973 which was a material document and, secondly that no finding had been given on the effect of unilateral deletion of the last sentence fr