The City of Ottawa may have to expand the amount of land it makes available for urban development by an additional 163 hectares.

Last June the Ontario Municipal Board ordered Ottawa to expand its municipal boundaries by 850 hectares, about four times what the city had wanted.

City lawyers thought that included a swath of land between Kanata and Stittsville known as "the Fernbank Lands" that is about ten times the size of Lansdowne Park.

But an OMB panellist said at a hearing Wednesday morning the Fernbank Lands were not part of the 850 hectares.

That took the city by surprise. City councillor Peter Hume, the chair of the planning committee, said he doesn't believe the panellist's interpretation of the original OMB ruling is correct.

"What's important is...the order they issued so we're going back to look at that position, because our understanding...and the understanding of everybody in that room, is different from what the OMB member has said," he said.

If the city does end up having to make an extra 163 hectares available, it will do so from a list of available parcels, including a lot north of Stittsville, one in Orleans, and another in Kanata, near the South March Highlands.