Back in January Tallgrass Energy, builder and operator of the mighty Rockies Express (REX) pipeline which is a critical link that flows Marcellus/Utica gas to Midwestern markets, dropped the bombshell announcement that investment firm Blackstone was buying a “controlling” interest in the company (see Blackstone Buys Controlling Interest in Tallgrass Energy). Blackstone now wants to buy the rest of the shares they don’t already own–and take Tallgrass private.