After months of speculation, Hip-Hop mogul Jay-Z announced on December 24 that he will officially vacate his position as President of Def Jam Records at the end of his term.The 38-year-old rapper issued a statement today (December 24) stating he will step down as president in 2008.“I’ve been incredibly fortunate to have served as President of such a culturally-defining label as Def Jam over the last three years,” Jay-Z said in a statement. “During that time, I’ve had the pleasure of working with many of the world’s most dynamic artists and many of the most dedicated and talented executives in the music business today, including Antonio “L.A.” Reid. But now it’s time for me to take on new challenges.”Jay-Z, born Shawn Carter, took over as President of Def Jam in 2005.Under his guidance, the rapper signed his former rival Nas to Def Jam and oversaw the release of hit records by Kanye West, Rihanna and Ne-Yo. The announcement serves to cap off a very turbulent year that saw Def Jam artists like LL Cool J protest that Jay as an artist and executive presented a unique conflict of interest. Additionally, a number of traditionally successful Hip-Hop acts like The Roots, Redman and Method Man failed to get traction under his reign. Island Def Jam Music Group Chairman Antonio “L.A.” Reid said that Jay-Z felt it was time to take on “different challenges in his life.””While we regret his decision to move on, we certainly respect it,” Reid said in a statement. “Since Jay joined us as President of Def Jam in 2005, we have all benefited from his leadership, sense of spirit and invaluable friendship. While he will continue to be one of our signature artists, he will nonetheless be missed in this executive capacity. The entire Island Def Jam family joins me in wishing him the very best in all of his future business endeavors.”Jay-Z will continue running and recording for his Roc-A-Fella imprint, which is distributed by the Island Def Jam Music Group. The mogul is rumored to be making a transition to the urban division of Sony Records with Rick Rubin. “I am pleased to have had the opportunity to build upon the Def Jam legacy, helping to move the company into a new era of artistic success,” Jay-Z said.Jay-Z’s American Gangster, inspired by the movie of the same name, has been received to critical acclaim,