Enbridge Inc. says the cost of its Line 3 replacement project has risen nine per cent from its original estimate when it was sanctioned in 2014.

The company now estimates it will cost $5.3 billion for the portion in Canada and US$2.9 billion in the United States to replace the pipeline that runs from Hardisty, Alta., to Superior, Wisc.

It attributed the higher cost to delays in the regulatory process and route modifications, among other changes.

However, the company said the impact of the increased costs on project returns are expected to be offset by lower operating costs and a strong U.S. dollar.

Enbridge said it expects to start construction in Canada this summer and have the pipeline in service in the second half of 2019.

The announcement came as Enbridge reported a second-quarter profit of $919 million or 56 cents per diluted share compared with a profit of $301 million or 33 cents per diluted share a year ago when the company had fewer shares outstanding.

Adjusted earnings for the quarter amounted to $662 million or 41 cents per share, up from $456 million of 50 cents per share a year ago.