Enbridge and Spectra Energy have agreed to merge their respective companies in a stock-for-stock transaction to create the largest energy-infrastructure conglomerate in North America.

Enbridge shareholders will own about 57 percent of the combined company and Spectra’s will own 43 percent, according to a statement released by the companies on Tuesday.

Al Monaco, president and chief executive of Enbridge, will continue in this capacity in the new company, while Gregory L. Ebel, president and ceo of Spectra Energy will serve as nonexecutive chairman. The headquarters will be in Calgary, where Enbridge is based.

The combined company's natural gas pipelines business would be based in Houston, and the liquids pipelines business would be based in Edmonton.

The companies are expecting to save about $415 million in costs, most of which will be achieved toward the end of 2018. Enbridge said it would divest $2 billion of noncore assets over the next 12 months to improve its balance sheet.

The companies expect the deal to close in the first quarter of 2017, although it is subject to shareholder approvals from both companies as well as regulatory clearance.