Adams' name has been banded around with the vacancy at Bramall Lane ever since Gary Speed left for Wales but, in a statement released on Christmas Eve, Port Vale confirm that they have 'reluctantly allowed' Adams to speak with the Blades.
The statement reads: 'Port Vale Football Club can confirm that it has received an official approach from Sheffield United to speak to manager Micky Adams.
Said Chairman Bill Bratt: "We have received an approach and we have reluctantly allowed Micky to speak to them.
"Micky is a terrific manager, who has been up front and honest with us throughout the process.
"It's testament to how well he has done at Port Vale that we have now been approached. Micky was offered a new contract before this happened and that is still on the table.
"We obviously want him to stay with Port Vale and I know everyone connected with the club feels the same."
Port Vale Football Club will not be making any further comment at this time.'
Adams has led the Valiants to second in the League Two table this season, only two points behind United's neighbours Chesterfield who lie in top spot.
The former Leicester and Coventry boss vowed to stay with the Staffordshire club for the long-term when he was appointed in 2009, but added that the only club which could realistically prise him away was Sheffield United.
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