The recruit to the 拢65,000 role will manage Expedia's 拢7m marketing budget and the portal's relationships with its agencies.
Smith left Expedia two weeks ago because she "wanted a new challenge".
She said it was too difficult to seek one while she was still in a job.
She also plans to spend time with her baby before finding a new role.
Smith appointed Zinc to the online creative account last June after a six-way pitch. Euro RSCG Wnek Gosper holds the above-the-line business, Media Planning Group plans and buys media and The Red Consultancy handles PR activity.
Expedia is 70% owned by Microsoft, where Smith worked before she was seconded to oversee marketing for Expedia.