NEW YORK (Reuters) – Noble Midstream Partners LP, a pipeline operator controlled by U.S. oil and gas exploration and production company Noble Energy Inc, is up for sale, people familiar with the matter said on Thursday.

Noble Energy could also decide to sell some of the assets and not the whole company, four sources said, asking not to be identified because the matter is confidential. Noble Midstream Partners LP is structured as a tax-efficient master limited partnership.

Oil and gas companies are coming under intense pressure from shareholders to direct their focus on their core operations to maximize returns and minimize expenses.

Noble Energy and Noble Midstream Partners did not immediately respond to requests for comment.