Mascaraque said in a statement that Ask.com is the fastest growing search engine and that it is "an exciting time to join".
"I have watched the brand set itself apart from competitors by pioneering new products and offering innovative ways of bringing search to users," he said.
"I look forward to working with the international teams to build on this already successful model."
Mascaraque will run European operations for Ask.com, having previously held the position of head of strategic partnerships and business development for southern Europe at Google.
Before his time at Google, Mascaraque was co-founder and director at online asset finance platform Finexia.com.
"With his extensive online expertise and tremendous business acumen, Mascaraque will be a great leader for Ask.com's European operations," said Jim Safka, chief executive at Ask.com.
Mascaraque replaces Myles Runham, who leaves after six years with the company he joined in 2001.
Runham was vice president of European operations and planning before being promoted to general manager for Europe in 2006.
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