Producers say the two groups are mashing up to close out 2011 on the ABC show.

The two bands, who have melded their monikers to become NKOTBSB, performed together live for the first time on the Dick Clark-produced American Music Awards last month. The supergroup plans to tour North America together next summer.

Pop singers Ke$ha and Taio Cruz are also set to perform from New York’s Times Square on the TV special hosted by Clark and Ryan Seacrest, which begins at 10 p.m. EST on Dec. 31 and ends around 2 a.m. on Jan. 1.

Other performers include Jennifer Hudson, Willow Smith, Ne-Yo, Avril Lavigne and Train.