Spending was undisclosed.
The distiller previously worked with a bevy of promotion shops on a contract basis.
"We're able to consolidate services currently being handled by several agencies at one company, which is more efficient and cost-effective," said Robert Shea, senior VP-sales and marketing for Hiram Walker.
"They wanted to get the efficiencies," said an executive at one promotion shop that works with Hiram Walker.
Hiram Walker's move brings it in line with Seagram Americas' longtime strategy of employing one agency-New York-based Seibel Marketing-for most brands.
Others, like Bacardi-Martini USA, either handle promotions in-house or work with numerous shops.
Flair previously did not handle any Hiram Walker brands, but it did do promotional work for Courvoisier cognac, distributed by sister company Domecq Importers.
Source Marketing, Westport, Conn., was agency of record for Canadian Club whiskey and also handled Kahlua liqueur; both brands are being moved to Flair.
But Source may be retained for project work.
MORE TIES MAY BE CUT
The status of Hiram Walker's relationships with other agencies has yet to be determined. Current contracts will be honored, but the distiller may cut ties after that, a spokesman said.
The roster "will shake itself out over the next 12 months," a spokesman said.
Some of the other promotion agencies Hiram Walker works with include I.D.8., Los Angeles; Quest, Bloomfield Hills, Mich.; and Ott Communications, Louis-ville, Ky.