Warren will be responsible for the day to day content on the site, and will report to Edward Roussel, digital editor of the Telegraph Media Group, who will continue to work on expanding the Telegraph's range of digital services.
Warren joined the digital team eight months ago, prior to which he was a foreign correspondent for the Daily Telegraph.
A spokeswoman for the Telegraph, said: "Marcus has played a key role in developing the website in recent months. In his new job he will be pushing forward all the changes to come in the months ahead."
Separately, Richard Preston has been appointed assistant editor of comment for the Daily Telegraph and .
Preston will be responsible for editing the comment pages of the paper and the site, and will oversee Telegraph online debates. He will also be responsible for blogs on ', TMG's new online community.
He has worked for the Daily Telegraph for nine years, and has held the positions of features editor and news editor. Since last autumn, he was assistant editor of Integration.
Preston replaces associate editor Simon Heffer who has been acting comment editor since last September. Heffer will remain chief political commentator at the paper..jpg)
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