Spanish term (edited): dar en caución títulos-suscribir letras en caución

Difficult to be sure without more context, but my understanding of "en caucion" would be that these things (deeds, etc.) are to be kept in the custody of a third party until a particular condition has been met. If this is right, then it would be "escrow deeds, shares etc."

My take

Note collateral is not used in the plural and they are not "transferred" - merely held

JPM Completes First Australian Tri-Party Securities Lending ...
https://www.globalcustodian.com/.../JPM-Completes-First-Aust...
The transaction allows UBS to provide securities as collateral instead of cash to borrow Australian securities from State Street Bank and Trust with a third party ...
legal uncertainty in cross-border collateral transactions
www.silverline-pub.co.uk/Securities/cross-border.htm
Likewise, the EU Finality Directive aims to impose a greater degree of legal certainty when parties provide securities as collateral held in custody accounts, ...
Payment Systems in Korea: - Google Books Result
https://books.google.com.ar/books?id=r4V1BgAAQBAJ
The Bank of Korea (Central Bank of South Korea) - 2010
(b) Collateral requirements Every RPS participant12) is required to provide securities as collateral against its possible settlement failure. In the event of a ...
J.P. Morgan first to launch Tri-Party securities lending AdviserVoice
https://www.adviservoice.com.au/.../j-p-morgan-first-to-laun...
Nov 30, 2010 - The unique transaction allows UBS to provide securities as collateral instead of cash to borrow Australian securities from State Street Bank and