  We study a model of two interacting levels that are attached to two
electronic leads, where one of the levels is attached very weakly to the leads.
We use rate equations method to calculate the average current and the noise of
electrons transmitted through the two levels. We show that the shot noise is
enhanced due to the interactions and that the Fano factor depends on the
properties of the couplings between the levels and the leads. We study both
sequential tunneling and cotunneling processes and show that there is a range
of parameters in which the cotunneling processes affect the noise
significantly, even though most of the current is carried by sequential
tunneling processes.
