CALGARY -- Kinder Morgan Canada Ltd.'s shares reversed course after trading higher following the federal government announcing it would buy its controversial Trans Mountain pipeline for $4.5 billion.

The shares were down about 0.60 per cent at $16.49 at noon ET on the Toronto Stock Exchange after going as high as $18. The company's stock had been halted prior to the announcement.

Ottawa is acquiring the existing Trans Mountain pipeline and the expansion project.

The company estimated the deal is worth about $12 per restricted voting share, after capital gains tax. It expects its approximately 30 per cent share of after-tax proceeds to be approximately $1.25 billion.

Kinder Morgan Canada will continue to hold an integrated network of crude tank storage and rail terminals in Alberta. It will also own a terminal in Vancouver and the Cochin Pipeline system which transports light condensate from the United States to Fort Saskatchewan, Alta.

The company had ceased all non-essential spending on the project until it receives assurances it can proceed without delays, setting a May 31 deadline on getting those guarantees.