Regasm tool fails to unregister interop assembly

I want to use C:\...\Framework\v4.0.310319\regasm.exe \u to unregister an interop assembly MyInterMain.dll that I've added previously also using regasm

This interop assembly has a reference to two other interop assemblies named myInterSub01.dll and myInterSub02.dll.

The steps I did to register them were

1. I created the interop assemblies by tlbimp Sub01.dll /out:MyInterSub01.dll and tlbimp Sub02.dll /out:MyInterSub02.dll
2. I created the main interop assembly by tlbimp Main.dll /out:MyInterMain.dll /reference:MyInterSub01.dll /reference:MyInterSub02.dll
3. I registered all of them by using C:\...\Framework\v4.0.310319\regasm.exe MyInterSub01.dll , C:\...\Framework\v4.0.310319\regasm.exe MyInterSub02.dll and C:\...\Framework\v4.0.310319\regasm.exe MyInterMain.dll

Now, as I want to change something, I try to unregister them in the following steps: 1. C:\...\Framework\v4.0.310319\regasm.exe MyInterSub01.dll 2. C:\...\Framework\v4.0.310319\regasm.exe MyInterSub02.dll 3. C:\...\Framework\v4.0.310319\regasm.exe MyInterMain.dll

These steps 1 and 2 are working as expected but when I execute step 3, I get an error message: "The file or assembly "MyInterSub01.dll", Version=2.0.0.0, culture=neutral, publickeytoken=null" or a dependency was not found. An Assembly with a strong name is required (Exception from HRESULT: 0x80131044)".