Seemingly unrelated regressions and instrumental variables

[Chang Seok]

Hi all,
I have a question regarding SUR and IV.
Currently, I have the following two regressions. (Different dependent variables but same independent variables)

And I am planning to use instrumental variable 'b_{i, t}' for 'a_{i, t}'
And I want to test whether beta_1 is equal to beta_2
I searched for SUR and found out that 'sureg' command is what I was looking for. But it seems like there are no options for instrumental variables in the command.
Is there another way to do this?

Thanks!