United confirmed the arrival of striker Montenegro on a season-long loan from Paraguayan top flight club Nacional – a deal which includes an option to buy him outright next summer – but the club sold Smith to Fulham minutes before the 11pm cut-off.
The Cottagers, who signed Ross McCormack from Leeds in a £10.75m transfer in July, targeted Smith yesterday just two weeks after the forward signed a new three-year deal at Elland Road. Fulham are understood to have paid a fee of £500,000.
Fellow striker Poleon joined Smith's former club Oldham Athletic for an undisclosed fee on a two-year deal.
In a separate development, Doukara’s loan from Catania was converted into a permanent deal just before the deadline.
The Frenchman, who is suffering from an ankle injury, originally joined Leeds on a season-long loan.