Tumblr founder and chief David Karp on Monday announced he is leaving the nearly 11-year-old blogging platform -- with his departure coming in the wake of Verizon buying parent-company Yahoo.

Karp said that he will leave by the end of this year and chief operating officer Jeff D'Onofrio will take his place at the helm of Tumblr.

"I beg you to understand that my decision comes after months of reflection on my personal ambitions, and at no cost to my hopefulness for Tumblr's future or the impact I know it can have," he said in a copy of a letter to employees that he posted online.