The petitioner in the first two writ petitions in W.P.Nos.23422 and 23734 of 2006 are cement companies and the petitioner in the third writ petition in W.P.No.24322 of 2006 is a Company engaged in installation and collection of fly ash collection system. In all the three writ petitions, the orders of the first respondent reducing the percentage of collection of fly ash allotted to the respective petitioners by the impugned orders are assailed. Except minor variations in respect of the period for which and the percentage of fly ash they were allowed to collect originally and the reduction in percentage by reason of the impugned orders, in all other respects, the facts are one and the same. As the grounds of attack, the arguments advanced to assail the orders and the defence put forth to sustain the impugned orders are one and the same, all the writ petitions are taken up together for disposal. For the sake of narration of facts, the first of the writ petition in W.P.No.23422 of 2006 is taken up as a typical case.

2. The facts of the case as culled out from the pleadings are as follows:

The petitioner in the course of their business entered into a memorandum of understandi