Hello Santhosh!
U can accomplish this with route-maps and dual ip nat commands.
For eg, lets say ur first local network is 192.168.1.0/16 and your second network is 10.1.0.0/16
And your isp1 address is 100.1.1.1 and your isp 2 address is 200.1.1.1...
access-list 100 permit 192.168.1.0 0.0.0.255
access-list 200 permit 10.1.0.0 0.0.255.255
route-map FOR_ISP1
match ip address 100
route-map FOR_ISP2
match ip address 200
int e0
ip nat inside
int s0
ip nat outside
int s1
ip nat outside
ip nat pool ISP1 100.1.1.1 100.1.1.1 prefix-length 24
ip nat pool ISP2 200.1.1.1 200.1.1.1 prefix-length 24
conf t
ip nat inside source route-map FOR_ISP1 pool ISP1 overload
ip nat inside source route-map FOR_ISP2 pool ISP2 overload
and
verify it by using ;
sh ip nat translation
sh ip nat stat
clear ip nat trans *
This should do the trick for U.
Try it out and please let us know.
Cheers
Arav