No, I'm afraid it's more complicated than that.
The initial episodes of UFO were shot at the MGM Borehamwood Studios -
across the road from the then EMI Studios (the remains of the latter are
the present Elstree Film Studios). The MGM studios closed part way
through shooting UFO, were never again used as studios and were
completely demolished years later. Confusingly, MGM moved in with EMI in
the present Elstree Film Studios and those studios became MGM-EMI
Studios for a while. Later, half of this site was sold to Tesco.
The present BBC Elstree Studios, also at Borehamwood but completely
separate to the above two studios began life as Neptune Film Studios.
Several incarnations later it was owned by ATV (the company, like ITC,
run by Lew Grade) and used as a TV studio. Because these studios were by
then fitted out as video studios, none of the ITC filmed series were
shot there. The filmed series were shot very much like B-movies by film
industry crews at various film studios.
The establishing shots of "Harlington Straker" Studios were shots of a
then-modern building on the ATV studios lot called Neptune House.
Presumably this was because the MGM studios were built in the 1930s and
didn't look futuristic enough and Neptune House was conveniently close.
Incidentally, you can see part of the admin building of the MGM studios
used as the exterior of a hospital in one episode of UFO.
After the MGM Studios closed, the rest of UFO was shot at Pinewood.
If all the above seems complocated it's partly because, over the years,
there have been several studios in and around Elstree/Borehamwood (off
the top of my head, 7?). Most of them having numerous names.
Images:
MGM Borehamwood:
http://www.tsf.net/~penrose/mgm.jpgArchitect's model of ATV Studios, showing Neptune House to the right:
http://www.tvstudiohistory.co.uk/images/ATV%20Elstree%20Studios,%20Model%20430.JPGRegards
John