Master limited partnership (MLP) Tallgrass Energy Partners LP (TEP) is acquiring an additional 25% stake in the Rockies Express Pipeline (REX) from privately held affiliate Tallgrass Development LP in a $400 million dropdown, the company said Monday.

The deal, which became effective March 31, brings TEP's total ownership stake in the 1,698-mile Appalachia-to-Rockies pipeline to roughly 50%. Tallgrass Development will still hold a 25% interest in the pipeline, with Phillips 66 owning the remaining 25%.

Tallgrass CEO David Dehaemers said management "[expects] the transaction to be immediately accretive to unitholders. We intend to recommend to the board of directors of our general partner that TEP increase its quarterly distributions for the second and third quarters of 2017 by an aggregate of at least 10 cents/unit or 40 cents/unit on an annualized basis."

Daily Markets Coverage, Analysis, & Price Data at 170+ Locations Since 1993

The Leawood, KS-based Tallgrass also said Monday that TEP will receive roughly 50% of a $150 million settlement payment from REX shipper Ultra Resources Inc., negotiated as part of Ultra's recent bankruptcy proceedings.

Ultra is expected to emerge from bankruptcy this month.

REX, whose volumes NGImonitors with its daily REX Zone 3 Tracker, has become a crucial  takeaway pipeline for the Marcellus and Utica shales since reversing flow on its eastern end a few years ago to offer east-to-west service out of Ohio.

REX kicked off 2017 by finishing work on its 800 MMcf/d Zone 3 Capacity Enhancement, which boosted total east-to-west volumes on the pipeline to 2.6 Bcf/d and had an almost immediate effect on regional pricing dynamics.

Tallgrass revealed during a 4Q2016 earnings call in February that it would be able to accommodate an additional 150 MMcf/d on top of the Zone 3 expansion.