The Villa manager also denied there is a clause requiring the Midlands club to make a £3 million payment to Sunderland if Bent makes 50 league appearances for the club.
The 28-year-old has so far clocked up 47 and has not featured on the bench for the past two matches since returning from injury.
Christian Benteke is firmly established as the number one striker with rookie Jordan Bowery preferred as a substitute to Bent.
Lambert said: "Have there been any enquiries for Bent? No. Has he asked to be put on the transfer list? No. Is there a clause? That's not true. I'm not sure where that came from."