Councillors are to meet next week to consider bids to turn the hall into a food market or a hotel, with council officials backing the food hall plan.
However a number of pre-conditions would need to be met before a draft lease could be agreed, at the authority's February meeting.
The B-listed Edwardian building has sat empty since it closed 10 years ago.
Councillors deferred a decision on which development bid to back, if any, in July, calling for further reports from Historic Scotland and other agencies and further information from the applicants.
At that stage, council officials had backed the view of independent property specialists Jones Laing LaSalle that the Perth Market Place Ltd proposal should be preferred to the hotel bid from the Seventy Group.
A report to councillors ahead of Wednesday's full council meeting noted that "there has been a change in circumstances which significantly impacts upon the Seventy Group's bid", meaning no further information could be provided.
Planning and development head David Littlejohn has asked councillors to give the marketplace proposal "preferred bidder status" to allow detailed negotiations to take place.
Should this happen, a draft lease could potentially be considered by the council in February 2016, although this would also have to be signed off by the Perth Common Good Fund Committee.
The Edwardian building, which dates back to 1911, was closed 10 years ago after a modern new concert hall was opened in the city.
Decisions over its future have been drawn out over a decade since then, with councillors at one point approving plans to have it demolished, which were subsequently blocked by Historic Scotland opposition.
The development management committee then backed the Seventy Group plans to convert it into a luxury hotel, before councillors agreed to publicly market a 125-year lease on the building to find an alternative to demolition.
Five bids were submitted in January, which where whittled down to two by July when councillors deferred the decision.
Should neither bid ultimately win approval, demolition could still be an option, although Historic Scotland chief executive Ian Walford warned he would be minded to object to such a move.
Mr Littlejohn also noted in his report that Historic Scotland had underlined that "the process cannot be allowed to perpetuate", and that a decision will have to be made.

The Conservative minister said he was inviting other political parties for talks on securing "the best possible devolution settlement for Wales".
A new UK cabinet committee chaired by Commons Leader William Hague will now meet for the first time on Wednesday.
Mr Crabb's comments come as Wales' First Minister Carwyn Jones called for a convention on future of the UK.
Speaking on Tuesday at the Labour Party conference, Mr Jones said the union cannot be rebuilt through conversation between only Westminster and Scotland.
Now the Welsh secretary has pledged to keep Wales at the discussion table on the future of devolved powers across Britain.
Mr Crabb said he had already held preliminary discussions with Mr Hague, a former Welsh secretary himself.
"We are both in absolute agreement that Wales should be central to the debate that is now commencing," said Mr Crabb.
"I want us to use this opportunity positively to look again at how we secure the best possible devolution settlement for Wales.
"I want to move forward in a realistic, open-minded and pragmatic way."
Mr Crabb has written to the leaders of other Welsh parties at Westminster inviting them to a Wales Office "summit" to discuss "how we deliver devolution that works for Wales".
The meeting is likely to take place when parliament returns next month.
He said he is also arranging meetings with party leaders in the National Assembly to ensure their views feed into the debate.
The comments from Mr Crabb came as Prime Minister David Cameron hosted discussions with backbench Tory MPs at his Chequers country residence.
One of the two Welsh MPs to attend was the Aberconway MP, Guto Bebb.
He said events in Scotland have "completely changed the nature of the debate" on devolution.
Key to Monday's talks have been the issue of "English votes for English laws", which would see Welsh and Scottish MPs excluded from voting on devolved matters in the House of Commons.
That has led to Labour Party leader Ed Miliband accusing Mr Cameron of planning to set the UK nations against each other.
But the Aberconway MP said he took a different view.
"The promises made to Scotland must be delivered upon and if they are delivered on then we are going to end up in my view with English votes for English laws and that in my view is a simple matter of fairness," said Mr Bebb.
A decision on the future of demolition-threatened Perth City Hall will not be made until February 2016.
[NEXT_CONCEPT]
Wales should be central in the debate on the UK union and devolution, Welsh Secretary Stephen Crabb has insisted.