On Friday, the Direct Marketing Association (DMA), which represents companies sending mailshots and other marketing material, wrote to the regulator objecting to Royal Mail's request, but adding that restrictions could be lifted in tightly defined circumstances.
Unless regulators object, it will become the world's pre-eminent defence-electronics and missiles company.
BHP ended its pursuit in November after Canadian regulators objected to a possible deal.
The failure of the proposed $17 billion three-way deal came after European regulators objected to the dominance that the planned combination would have exerted.
European Union regulators objected, saying the combined company's control of European production of flat-rolled aluminum, the kind used in cans and foil, would be too great.
An attempt last year by Pure Gym to merge with the discount chain Gym Group was abandoned after regulators objected to the deal.
The plan to unite Alcan, Algroup and Pechiney failed after European Union regulators objected to the dominant position that the combined companies would have had in Europe and after Alcan refused to divest itself of European factories.
The failure of the proposed $17 billion three-way deal to create the world's leading aluminum company came after the European Union's antitrust regulators objected to the dominance that the planned combination would have exerted in Europe's aluminum industry.
Setanta got its opening because European regulators objected to a long-running, exclusive relationship between the league and British Sky Broadcasting, which is controlled by News Corp. Sky has retained a majority of the matches since then, but Setanta won the rights to broadcast 46 games a season, one-third of the total, from 2007 through the 2009-10 season.
BHP's recent rebuff by Canada's government in its quest to buy PotashCorp and before that the collapse of an iron-ore joint venture with Rio, after regulators objected, show the difficulty of completing a mega-mining deal these days.
