  Suppose that $\alpha \in (0,2)$ and that $X$ is an $\alpha$-stable-like
process on $\R^d$. Let $F$ be a function on $\R^d$ belonging to the class
$\bf{J_{d,\alpha}}$ (see Introduction) and $A_{t}^{F}$ be $\sum_{s \le
t}F(X_{s-},X_{s}), t> 0$, a discontinuous additive functional of $X$. With
neither $F$ nor $X$ being symmetric, under certain conditions, we show that the
Feynman-Kac semigroup $\{S_{t}^{F}:t \ge 0\}$ defined by $$
S_{t}^{F}f(x)=\mathbb{E}_{x}(e^{-A_{t}^{F}}f(X_{t}))$$ has a density $q$ and
that there exist positive constants $C_1,C_2,C_3$ and $C_4$ such that
$$C_{1}e^{-C_{2}t}t^{-\frac{d}{\alpha}}(1 \wedge
\frac{t^{\frac{1}{\alpha}}}{|x-y|})^{d+\alpha} \leq q(t,x,y) \leq
C_{3}e^{C_{4}t}t^{-\frac{d}{\alpha}}(1 \wedge
\frac{t^{\frac{1}{\alpha}}}{|x-y|})^{d+\alpha}$$ for all $(t,x,y)\in (0,\infty)
\times \R^d \times \R^d$.
