Ms. Quinlan is succeeded as CEO by Mary Beth Casey, who also will retain the Ayer president title she was given earlier this year.
The new venture, as yet unnamed, is expected to service a variety of MacManus' clients, including those of sister shop D'Arcy Masius Benton & Bowles.
Ms. Quinlan has already signed on to be a motivational coach for a group of senior women at one undisclosed client. For another client, she will offer counsel on how to coordinate global communications in the new millennium.
While running the consultancy, she will stay in close contact with key Ayer clients. MacManus Group Chairman-CEO Roy Bostock said Ms. Quinlan will dedicate 50% of her time to servicing General Motors Corp., Avon Products and Continental Airlines.
"It's a dual responsibility," said Mr. Bostock of Ms. Quinlan's consulting and remaining Ayer duties.
Ms. Quinlan also hopes to expand her talk-show-style "Just Ask a Woman" research program into TV and online areas. She said she's currently looking into cable and women's programming options.
The executive said she took the month of November off to ponder how she could further her career. In December, she presented the consultancy option to Mr. Bostock.
Ms. Quinlan said her overriding goal is to be the "world's most compelling interpreter of how to increase market-share relevance and loyalty among women." All the while she'll be nursing her secret dream to become a talk-show host.
Ms. Quinlan's move comes just weeks in advance of a major change in MacManus' media buying and planning operations.
Next month, the parent will announce a new, standalone global media arm that will be over TeleVest and all other MacManus media operations.
Executives close to the agency said there also had been discussions within the MacManus Group structure about the possibility of merging DMB&B and Ayer and eliminating the name of Ayer, one of the nation's oldest ad agencies.