Remove Bearing Wall under part of a Floor Girder Truss

[BR22]

I have a floor girder truss that has about a 6 ft. section in the middle that is supported by an existing bearing wall. My client wants to remove the bearing wall and add a beam. However the beam isn't just replacing the 6 ft. section of wall. The beam is going to be about 12 ft. long. I don't have a lot of experience with truss design. If I add a new beam underneath the existing girder truss, will it negatively affect the portions of the truss that weren't designed to be bearing on something? or will it not really matter since the beam will be designed to carry the load?

I can also specify that the remainder of the truss be supported by bearing walls if needed. So then the whole truss would be supported.

I attached a sketch to show the general idea of what I'm talking about. The existing truss profile is not accurate, just an estimate. I haven't seen the truss in person yet because no demolition of the ceiling has happened yet, so I'm assuming that it has a different profile over the existing bearing wall than it does for the rest of the truss.

 

[BAretired]

The new beam should be designed to carry the full load from above. The existing trusses should be laterally braced so that they will not roll over, but otherwise should not be affected by the new beam.