Let D be a bounded domain with a smooth orientable \(C^ 2\) boundary \(\Omega\) in \({\mathbb{C}}^ n\). Let B(x,\(\epsilon)\) be the open ball of radius \(\epsilon\) of Euclidean distance and center at x, \(s(x,\epsilon)=\Omega \cap B(x,\epsilon)\) and \(S(x,\epsilon)=\Omega \setminus s(x,\epsilon)\). Let K(x,z) denote the B-M (Bochner-Martinelli) kernel, a complex exterior differential form of type (n,n-1). For a function \(\phi\) in H(\(\alpha\),\(\Omega)\) satisfying Hölder condition of order \(\alpha\), the singular integral \(\int_{\Omega_ x}\phi (x)K(x,z)\) is to take the Cauchy principal value \(\lim_{\epsilon \to 0} \int_{S(z,\epsilon)}\phi (x)K(x,z).\) The author first derives the composite formula \(\int_{\Omega_ y}K(y,z)\int_{\Omega_ x}h(x)K(x,y)=h(z)/4,\) where h(x) is of type (n,n-1) whose coefficients belong to H(\(\alpha\),\(\Omega)\). Then the following theorem for transformation formula is obtained. If h(x,y) is a complex differential form of type (n,n-1), whose coefficients belong to H(\(\alpha\),\(\Omega)\) with respect to x and y, and if \(z\in \Omega\), then \[ \int_{\Omega_ y}K(y,z)\int_{\Omega_ x}h(x,y)K(x,y)=\int_{\Omega_ x}\int_{\Omega_ y}h(x,y)\quad K(y,z)K(x,y)+(1/4)h(z,z). \] Using these formulae, the author considers the singular integral equations \(a\phi +bK\phi +H\phi =f,\) where f is of type (n,n-1) belonging to H(\(\alpha\),\(\Omega)\), and K and H are integral operators with B-M kernel K(x,y) and a kernel H(x,y) belonging to H(\(\alpha\),\(\Omega)\) respectively. Solutions to the equations are discussed for the cases where a and b are complex constants, vectors and functions in H(\(\alpha\),\(\Omega)\) with \(a^ 2-b^ 2\neq 0\) on \(\Omega\).