M.R. SHAH, J.

1. As common question of law and facts arise in this group of petitions and as such arise out of the impugned common judgment and order passed by the learned Gujarat Sales Tax Tribunal, Ahmedabad (hereinafter referred to as "Tribunal") passed in Appeal Nos.4/2005 to 23/2005 as well as the common order passed by the learned Tribunal in respective Rectification Applications, all these petitions are decided and disposed of by this common judgment and order.

2. For convenience, Special Civil Application No.12980/2007 arising out of the impugned judgment and order dated 16.05.2005 passed by the learned Tribunal in Appeal No.17/2005 and the order dated 06.07.2006 rendered in Rectification Application No.34/2005 be treated as the lead matter.

3. The facts leading to the present Special Civil Applications in nutshell are as under:

[3.1] That the Oil and Natural Gas Corporation (hereinafter referred to as "ONGC") is the purchaser of natural gas in India. According to the petitioner State of Gujarat, earlier ONGC used to market the gas directly to its consumers. However, later on, for administrative convenience, manufacturing activity was separated from marketing activity a