  We consider a network of bank holdings, where every holding has two
subsidiaries of different types. A subsidiary can trade with another holding's
subsidiary of the same type. Holdings support their subsidiaries up to a
certain level when they would otherwise fail to honor their financial
obligations. We investigate the spread of contagion in this banking network
when the number of bank holdings is large, and find the final number of
defaulted subsidiaries under different rules for the holding support. We also
consider resilience of this multilayered network to small shocks. Our work
sheds light onto the role that holding structures can play in the amplification
of financial stress. We find that depending on the capitalization of the
network, a holding structure can be beneficial as compared to smaller separated
entities. In other instances, it can be harmful and actually increase
contagion. We illustrate our results in a numerical case study and also
determine the optimal level of holding support from a regulator perspective.
