For the record: Bernsen’s International Press Service – BIPS and I’ll try to find the agency stamp and upload it here.
I received this information on BIPS  from photographer Frank Martin: Formed by Theo Bernsen who began his press career by running an underground news paper in Nazi Occupied Holland.
He formed a features agency working from a three floor building in Garrick Street, serving magazines and papers in Britain and world wide, concentrating on features which had some ‘life’. In other words he was not very interested in door-stepping but looked for pictures and stories which would sell again and again. BIPS made a good living from the many picture magazines which proliferated in the fifties and sixties: Stern, Paris Match, Le Ore, l’illustre and so on. Harry Kerr [The Times] and Frank Martin [The Guardian] get their foot into Fleet Street via BIPS.
When the magazine market began to contract and Theo died the archive was taken over by Bill Habets whose last known address and phone number was in Eastbourne.

About Frank Martin:
“Hi Will, Glad the info may be of help. While at BIPS I freelanced for The Sunday Telegraph, Sunday Times and The Guardian. Eventually going to The Guardian as a staffer and remained there until I retired in ‘97. I also have found a pic of a group of Guardian Snappers, most of whom have a Fleet street agency origin. If it is useful I can download it. It was taken at a funeral of Brian Crook, another old Fleet Street hand.” (Frank has not sent the image yet)
Update: 12 April 2020:
Jim Powell, Picture editor at The Observer contacted us last week with news of Franks death. They have run a smashing piece to him featuring a gallery of his images and linking back to us …Thanks! RIP Frank.
Jim has sent me a few of Franks images to run on the PPHP.

David Hockney, The Artist’s Eye exhibition, The National Gallery June 1981 – Photograph suppled: Frank Martin/The Guardian

Harold Wilson lighting his pipe – Photograph supplied: Frank Martin/The Guardian

Judi Dench at home in 1977 – Photograph supplied: Frank Martin/The Guardian

Osmond mania at Earl’s Court concert – Photograph supplied: Frank Martin/The Guardian