Using an algebraic orbifold method, we present non-commutative aspects of
G2 structure of seven dimensional real manifolds. We first develop and solve
the non commutativity parameter constraint equations defining G2 manifold
algebras. We show that there are eight possible solutions for this extended
structure, one of which corresponds to the commutative case. Then we obtain a
matrix representation solving such algebras using combinatorial arguments. An
application to matrix model of M-theory is discussed.Comment: 16 pages, Latex. Typos corrected, minor changes. Version to appear in
J. Phys.A: Math.Gen.(2005