FILE PHOTO - Tumblr Founder and CEO David Karp poses on the north side of the White House in Washington, June 10, 2014. REUTERS/Larry Downing

(Reuters) - Tumblr founder and CEO David Karp will step down after more than 10 years at the helm of the blogging service, he said on Monday.

"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," Karp said in a letter to staff. bit.ly/2AC0SFM

Tumblr is part of Verizon's VZ.N Oath business, which houses Yahoo and AOL internet properties. Yahoo bought Tumblr for $1.1 billion in 2013.

Jeff D’Onofrio, Tumblr’s chief operating officer, will continue to lead Tumblr after Karp steps down by the end of the year, an Oath spokeswoman said via email.

Tumblr, founded in 2007, grew rapidly to become a hub for young people to post pictures and text. The platform has almost 380 million blogs.