(In 2nd paragaph, corrects Calgary's location to Alberta, not British Columbia)
By David French
NEW YORK, April 5 (Reuters) - Pipeline operator TransCanada Corp is exploring a potential sale of its Columbia Midstream unit in a deal that could value the business at about $1 billion, three sources aware of the matter said on Friday.
TransCanada, based in Calgary, Alberta, is offloading parts of its infrastructure to help finance the $8 billion it has earmarked to spend on new projects in 2019, such as the high-profile Coastal GasLink system and the Keystone XL pipeline, which are likely to generate higher returns than these legacy assets.
A sale of Columbia Midstream is not guaranteed, and TransCanada's plans could still change, the sources cautioned, asking not to be named because the information is private.
A spokesman for TransCanada declined to comment.
Columbia Midstream's assets include four gathering systems and a pipeline in eastern Ohio and western Pennsylvania, according to the company's website.
The unit generates around $100 million of earnings before interest, tax, depreciation and amortization annually (EBITDA), and could be valued at a multiple of 10 times that amount, the three sources said.
Private equity firms, infrastructure and pension funds have all viewed pipeline assets as attractive acquisitions because of their steady financial returns.
TransCanada is working with an investment bank to assist it in the sale process.
TransCanada is also selling a package of mineral rights in the same area, located in the Appalachian region of the eastern United States, which would raise further cash for the company, one of the sources said.
Mineral rights grant the holder the ability to extract hydrocarbons from certain acreage, although the title to that land is held by another party.
The mineral rights could be sold to the same buyer as the midstream unit, but if the company receives a better offer from another party, they could be sold separately, the source said.
TransCanada's chief financial officer, Donald Marchand, said on the company's fourth-quarter earnings call in February that the company could divest assets that generate $500 million of EBITDA without identifying what they were. (Reporting by David French; Additional reporting by Nia Williams in Calgary; Editing by Liana B. Baker and Leslie Adler)