Solberg will use a Citroen DS3 in both the revamped FIA-sanctioned European RX championship and the American-based Global Rallycross series, plus the X Games.
"Where else could I remain in a powerful all-wheel-drive turbo which is more or less a WRC car aside from the extra 300hp, and have between five and eight others around me spitting fire as well?" said Solberg. "That to me is just too hard to pass up.
"I really want to become a champion at least one more time in my career. I am a showman and I want to make some noise. Rallycross will fit me perfectly."
The 2003 WRC title-winner began his career in rallycross in the mid-1990s.
"In 1996, I actually considered the European Rallycross series for my long-term future but it turned out that rally would pull me in," Solberg added.
The Norwegian, who lost his WRC Ford seat at the end of last season, will make his first competitive appearance of 2013 on Rally Sweden next weekend, when he contests the parallel historic event.