Merger & Acquisition – Market Strategy or Monopoly

Jacobs bought Aker Solutions and Sinclair Knight Merz. AMEC merged with Foster Wheeler. Halliburton bought out Baker Hughes. The next big one, Shell planned acquisition of British Gas (BG) for nearly $70bn. Shell and BG merger will create the world’s 2nd largest oil company next to ExxonMobil.

Are these mergers and acquisitions part of marketing strategy or just plain monopoly? How does this differ from the anti-trust ruling against Microsoft?