She takes on the new role this week in addition to becoming president of the firm's operation across EMEA and Australia and New Zealand. She was previously MD for the two regions.
MacLaverty, who has been with Hotwire since 2004, is based in London.
It is the latest senior move at the firm. After CEO Brendon Craigie left Hotwire in March, last month it promoted Bates to the role, just seven months after she joined the company when it acquired her agency Eastwick.
Bates said: "The next three years are going to be pivotal for Hotwire as we seek to expand our reach even further in terms of our offering, client base and operations... Alex's strong vision for the business and proven leadership skills, combined with her experience and expertise in driving our performance above and beyond will be critical in achieving our goals."
MacLaverty said the firm's leadership had "put together a plan for the next three years to make a lot of investments and grow the business". While she would not be drawn on particular targets for its growth, she said that they would include increasingly offering services beyond traditional PR such as insights and "CMO-focused services... strategic services that deliver business results".
Hotwire, which is owned by Australian group Enero, will also aim to improve its employer brand and become "go-to employers in the PR space", according to MacLaverty.
The firm is planning to add further senior talent to achieve these goals, she said.
MacLaverty also reiterated Bates' statement last month that the nine-office, 250-employee group was on to register its biggest year in revenue terms in the year ending 30 June. The Global Agency Business Report shows Hotwire's 2016 revenue was $31.7m, up 35 per cent on the year before.