Canadian oil pipeline operator Enbridge will buy US rival Spectra Energy for Can$37 billion (US$28 billion) in an all-stock deal, the companies announced Tuesday.

Enbridge shareholders will own 57 percent of the merged company. Spectra Energy shareholders will receive 0.984 shares in the merged company for every share of Spectra Energy they own. Based on this, Spectra Energy shares are being valued at US$40.33, or 11.5 percent higher than at last closing, according to the companies.