A decree signed by President Vladimir Putin said RIA Novosti and the state-owned Voice of Russia radio broadcaster would be absorbed into a new media entity called Rossiya Segodnya, RIA Novosti reported.
RIA Novosti said the change was the latest in tightening control over Russia's already heavily regulated news reporting.
Separately Monday, the Kremlin appointed Dmitry Kiselyov, a prominent conservative Russian TV personality and media manager recently caught up in a scandal over anti-gay remarks, to lead Rossiya Segodnya.
Sergei Ivanov, head of the presidential administration, said the changes would save money and make state media more effective.
"Russia has its own independent politics and strongly defends its national interests. It's difficult to explain this to the world but we can do this and we must do this," Ivanov said.
Rossiya Segodnya translates to "Russia Today," but the new media entity apparently will be separate from RT, the Kremlin-funded English-language television channel originally known as Russia Today, RIA Novosti reported.
RIA Novosti, which began in 1941 as the Soviet Information Bureau, has reporters in more than 45 countries.