We obtain (3 + 3)- or (3 + 2)-dimensional global flat embeddings of four un
charged and charged scalar-tensor theories with the parameters B or L in 2
+ 1 dimensions, which are the nontrivially modified versions of the Banados
-Teitelboim-Zanelli (BTZ) black holes. The limiting cases B = 0 or L = 0 ex
actly are reduced to the global embedding Minkowski space solution of the B
TZ black holes.