The phrase "agreed provided that" is correct and usable in written English.
It can be used to indicate that an agreement is contingent upon certain conditions being met.
Example: "I am willing to collaborate on this project, agreed provided that we can finalize the budget first."
Alternatives: "agreed as long as" or "accepted on the condition that".
Mr. Lieberman agreed, provided that it fit into his schedule.
Mr. Calabro agreed, provided that he mowed the grassy lot every few weeks and found a bathroom elsewhere.
They agreed provided that, if the game was a success, I'd find an alternative manufacturer, as they didn't want to be stuck making little blocks for the rest of their lives.
After initial disbelief, Daimon agreed, provided that other veterans would have access to similar services.
The researchers and the journals agreed, provided that the U.S. government comes up with a mechanism to share those details with bona fide researchers and public health experts.
The Andalusians agreed, provided that Asbagh was recognized as the overall commander, and together with fresh troops from Ifriqiya marched on Mineo.
"My boss has graciously agreed, providing that it increases my output, to the use of the computer room next door to my office," Ms. Moskowitz writes.
The War Office agreed, providing that the body could be identified, but the Foreign Office was more reluctant and pointed out that a licence for exhumation would have to be authorised by the Home Office.
The award, it was agreed, provided ample vindication for that decision.
We also asked the participants if they agree that provided that potential organ donors did not choose the "opt-out" option during their lifetimes, it should be possible to retrieve their organs after death against the will of the relatives, as the intention of the deceased person is not reproducible anymore.
Just Energy bought the power from the Lone Star II wind farm and has agreed to provide that power to residential and small business customers who (because of their size) could not otherwise contract directly with the renewable plant themselves.
