Maybe you found a solution in the meantime, otherwise this could maybe help.
Your request could be solved with a VBA-function (ConcatRelated) that's developed by Allen Browne. I attached a file with the function. If you import this as a module in your database, you should be able to use the ConcatRelated-function in a query like this:
SELECT ConcatRelated("PID","ContractDetails") AS PID, Contract AS [Contract#], SUM([Pre-Tender]) AS [Pre-Tender SubTotal], SUM(Awarded) AS [Awarded SubTotal]
GROUP BY Contract;
This is the query output:
I named the table ContractDetails, but you can replace it with yours. Note that you have to replace it in the call to ConcatRelated() as well.
Hope it works.