CALGARY -- Enbridge Inc. says it expects integrity testing on its Line 9B pipeline between southern Ontario and Montreal to wrap up by year-end.

The Calgary-based company (TSX:ENB) had hoped to begin shipping Alberta crude through the line last fall, but the National Energy Board isn't allowing it to start up yet.

In June, the regulator ordered Enbridge to conduct hydrostatic testing on three densely populated segments of the pipeline, though some groups in Ontario and Quebec are demanding testing along the whole line.

The tests involve filling the pipe with water at high pressure to ensure there aren't any leaks.

Earlier, the National Energy Board raised concerns about the placement of shut-off valves, which it says Enbridge has now addressed.

The CEO of Suncor Energy, whose refinery in Montreal would process crude from Line 9, expressed disappointment with the delays on a conference call Thursday.

"Of course we completely support the need for stringent safety and environmental controls," Steve Williams said. "But the length of this process in our judgment has been too long."

The original Line 9 has been in the ground for decades, most recently shipping imported crude westward. But with burgeoning production in the West, it now makes more sense to ship domestic crude eastward so that refineries don't need to buy crude from abroad.

The National Energy Board conditionally approved the project to reverse and ship more crude through the line in March 2014.

"The timeline on this is really going to depend on when we can get into the field to do the additional confirmation testing that the NEB is requiring us to do. We've planned that out now. The NEB has approved the confirmation testing plans, so that's underway," Enbridge CEO Al Monaco told analysts Friday.

"After we complete that testing, from there the NEB will review the results and then they will determine when we can start operations. At that time, we hopefully will be ready to fill the line with crude and so in general terms it's probably going to be into the fourth quarter before we get full clarity on that."

Earlier Friday, Enbridge posted second-quarter adjusted net earnings of $505 million, up from $328 million a year earlier. Those figures strip out the effects of usual items.

Earnings attributable to common shareholders, which account for factors like hedging and impairment charges, dropped to $577 million from $756 million a year earlier.

While oil producers reel from a halving in crude prices from a year ago, Monaco said demand for capacity on Enbridge's vast mainline system remains strong.

"In the current price environment, cost effective, reliable access to key markets is even more critical for our customers," he said in a release.