Toronto-area real estate agents will be allowed to publish details about house sale prices under a Federal Court of Appeal ruling released Friday in a long-running battle over data privacy.

The court ruled that the Toronto Real Estate Board cannot prevent its members in the Greater Toronto Area from publishing details about how much properties sold for, saying there are no privacy concerns that restrict publication.

In a statement late on Friday, TREB said it is disappointed by the decision and will seek leave to appeal to the Supreme Court of Canada. The association said it will apply for a court order staying the release of data until the appeal is decided.

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"TREB believes strongly that personal financial information of home buyers and sellers must continue to be safely used and disclosed," chief executive officer John DiMichele said.

TREB has spent years opposing Competition Bureau moves to open more data from its Multiple Listings Service to the public, arguing home sellers have not given approval for private sales information to be published broadly.

The MLS database publicly displays current listings of homes for sale and their asking price, but real estate agents who are TREB members have access to far more information that is not displayed publicly, including sales prices, historic sales and realtor commissions.

TREB allows its members to share historic sales information with individual clients, but they cannot publish the data in bulk online, even on password-protected data feeds.

Friday's court ruling upheld a Competition Tribunal decision in 2016 that ordered TREB to open up its MLS data for realtors to post online. The court said that the tribunal was correct when it decided there is no breach of privacy rights for clients when pricing data is revealed by TREB realtors online through data feeds for clients.

The real estate board argued that allowing the data to be published broadly would violate privacy rights, arguing that homeowners could give approval in the future for sales data to be published, but such approvals were never obtained in the past for information dating back to the 1980s.

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However, the Competition Tribunal decision noted that the data is already available to more than 42,000 Toronto realtors and many more members of other Ontario real estate boards. Realtors are also allowed to distribute sales-price data to up to 100 of their clients at a time.

Lauren Haw, CEO of Toronto-based Zoocasa, which provides home and neighbourhood data for home buyers, said her firm will not immediately begin to publish sales prices because it will wait for TREB to conclude its appeals and then outline how it will permit the data to be displayed.

Ms. Haw said the ruling will allow a firm like Zoocasa to provide much more analytical information along with data. The firm could show buyers sales-price trends for several comparable homes in their area, or data on homes that are being flipped after a recent purchase. She said Zoocasa could put alerts on homes that are being listed for below recent sales prices.

"There will be some interesting things we can play with," she said.

Toronto realtor John Pasalis said he is happy with Friday's ruling, arguing clients deserve to have more tools to do their own research about home transactions.

"Let them do their own research so they're not buying a house blind," Mr. Pasalis said. "Now they're relying on the sold data provided by their agents, and however their agent wants to filter sold listings for them."

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He said the ruling will also make it easier for do-it-yourself sellers to list their homes on their own and obtain the data they need, which means realtors will have to raise their own games and work harder to justify their services.

"We have to raise the bar in the real estate industry, because in the past the big value-add that realtors had was they had access to MLS and you didn't. But when all that stuff is a commodity and it's available to people, agents will have to change significantly."

Ms. Haw, however, said she doesn't anticipate a large increase in people selling homes themselves because that has not been the trend in the United States, where sales data has been available. People still prefer to work with agents for other reasons than just access to data, she said.

While Friday's ruling applies specifically to TREB, it is anticipated to set a wider precedent for other real estate boards across Canada, which are also facing pressure to allow more data to be released publicly.

Many companies and individual real estate agents have previously attempted to provide access to data through subscription sites, but have ended up being forced to shut them down.