Manchester United have yet to receive the full balance for the sale of Jaap Stam to Lazio.

The amount outstanding, believed to be �12m, is required to offset the money owed to Leeds for the purchase of Rio Ferdinand.

Stam signed for the Serie A club for �16.5m 13 months' ago.

The Old Trafford outfit have to pay Leeds �14.3m next summer as the second instalment of the deal which will ultimately cost �33m.

Lazio have endured financial difficulties during the past 12 months and Manchester United have applied to Uefa to arbitrate over a new payment schedule.

The news comes a day after Manchester United announced pre-tax profits of �32.3m.

Significantly, the figures did not include the money spent in the Ferdinand deal.

On the pitch, the team face Olympiakos in the Champions League on Tuesday and they could be without top striker Ruud van Nistelrooy.