two outside nat interface

Hi evrybody…

is possible to set 2 interfaces as outside interface for nat?

I have port 2 with vlan X and port 4 with vlan Y. Each Port is connected to teh same router and each one has OSPF protocol configured.

When the Link with VLAN X is down, the OSPF adjacency is formed with the port with the vlan Y, but i have to change manually the Outside interface to VLAN Y for the internet traffic.