For IOS12.2.18 you can create a maximum of 128 etherchannels, subject to the constraints listed above.

For CATos  I bleieve ther is a limitation in some chassis to 63.

Beware of trying to port-channel interfaces across different line cards. The QoS scheduling can be different and not allow a port-channel to come up. See the difference below:

sh int te7/12 cap

TenGigabitEthernet7/12

  Model:                 WS-X6716-10GE

  Type:                  10Gbase-SR

  Speed:                 10000

  Duplex:                full

  Trunk encap. type:     802.1Q

  Trunk mode:            on,off,desirable,nonegotiate

  Channel:               yes

  Broadcast suppression: percentage(0-100)

  Flowcontrol:           rx-(off,on),tx-(off,on)

  Membership:            static

  Fast Start:            yes

  QOS scheduling:        rx-(1p7q2t), tx-(1p7q4t)

  QOS queueing mode:     rx-(cos,dscp), tx-(cos,dscp)

  CoS rewrite:           yes

  ToS rewrite:           yes

  Inline power:          no

  Inline power policing: no

  SPAN:                  source/destination

  UDLD                   yes

  Link Debounce:         yes

  Link Debounce Time:    yes

  Ports-in-ASIC (Sub-port ASIC) : 9-16 (9-12)

  Remote switch uplink:  no

  Dot1x:                 yes

  Port-Security:         yes

sh int te6/1 cap

TenGigabitEthernet6/1

  Model:                 WS-X6708-10GE

  Type:                  10Gbase-SR

  Speed:                 10000

  Duplex:                full

  Trunk encap. type:     802.1Q,ISL

  Trunk mode:            on,off,desirable,nonegotiate

  Channel:               yes

  Broadcast suppression: percentage(0-100)

  Flowcontrol:           rx-(off,on),tx-(off,on)

  Membership:            static

  Fast Start:            yes

QOS scheduling:        rx-(8q4t), tx-(1p7q4t)

  QOS queueing mode:     rx-(cos,dscp), tx-(cos,dscp)

  CoS rewrite:           yes

  ToS rewrite:           yes

  Inline power:          no

  Inline power policing: no

  SPAN:                  source/destination

  UDLD                   yes

  Link Debounce:         yes

  Link Debounce Time:    yes

  Ports-in-ASIC (Sub-port ASIC) : 1,4-5,7 (1)

  Remote switch uplink:  no

  Dot1x:                 yes

  Port-Security:         yes

This is the error you will see:

%EC-SP-5-CANNOT_BUNDLE2: Te7/12 is not compatible with Te6/1 and will be suspended (qos-card types of Te7/12 do not match Te6/1)

Enter the command below on the port-channel to allow the grouping of the ports

#no mls qos channel-consistency

That being said I hope I can bundle interfaces of different optic types i.e. 10Gbase-SR and 10Gbase-LRM