CALGARY - Suncor Energy (SU.TO) is revising its estimates on when full shipments from its Mildred Lake oilsands operation will resume following a fire in March.

At the beginning of May, Suncor said repairs had been completed and production was expected to return to full rates in June.

On Tuesday, the company issued a news release saying the timing of full ramp-up has been extended to mid-July.

The company said repairs are progressing as planned but maintenance work scheduled for the fall has been added, so shipments have been reduced to allow for that.

The company said the maintenance work had been included in the 2017 production plan so there is no change to Suncor's overall production guidance for the year.

The cause of the March incident was a split in a six-inch carbon steel line on a naphtha hydrotreater recycle circuit.