The $15.75 per common unit offer represents a premium of 11.3% to Columbia Pipeline Partners' 30-day average closing price as of Sept. 23, TransCanada said.
A committee of independent directors of Columbia Pipeline Partners' board will be formed to consider the offer as the general partner of Columbia Pipeline Partners is an indirect unit of Columbia Pipeline Group, TransCanada said.
TransCanada, which completed its $10.3 billion takeover of Columbia Pipeline Group in July, had said it was reviewing strategic alternatives for MLP holdings, including Columbia Pipeline Partners LP.
Columbia Pipeline Partners LP is a Delaware MLP with interests in three regulated U.S. natural gas pipelines, as well as storage and related midstream assets.
TransCanada, Canada's second-largest pipeline company, has retained Morgan Stanley as its financial adviser and Vinson & Elkins as legal adviser.
Oryx II is the second midstream monetization for WPX in 2019.
Partners Group, which manages $84 billion worth of assets, said it was looking to make more acquisitions in Norway.
H2O Midstream's acquisition is concurrent with the execution of an acreage dedication based midstream water services agreement with Encana for a portion of its Permian Basin position.