( 1 ) THIS common judgment will dispose of both the writ petitions as they are interconnected. The petitioner in WP No. 7004/88 is the Andhra Pradesh Dairy Development Co-operative Federation Ltd. Workers Union represented by its General Secretary and the respondent is the Guntur District Milk Producers Co-operative Union Limited (Sangam Dairy) represented by its General Manager. On 23/03/1985, a settlement under Section 12 (3) of the Industrial Disputes Act. 1947, was reached between the management of the Sangam Dairy and the petitioner-union and another union by the name Bharatiya Mazdoor Sangh, both registered unions. The Sangam Dairy was declared as a public utility service as stated in the memorandum of settlement. The settlement reached between the parties covers nine matters; paragraph 4 which concerns with the seniority list of workers employed on Nominal Muster Rolls (NMRs) reads as follows :"the management have also agreed to prepare the seniority list of the workers working on nominal muster rolls before the end of April, 1985, and fix up to notice board under copy to the Unions. Preference would be given to the NMR workers in the matter of any regular appoi