Manchester United have lodged a world record offer for Napoli defender Kalidou Koulibaly.

Corriere dello Sport says United made the €105m bid late, last month.

The proposal remains on the table, with Koulibaly's contract carrying a €150m buyout clause.

It isn't the first offer from United for the stopper, with Napoli president Aurelio de Laurentiis admitting earlier this season he'd rejected a major offer for Koulibaly last summer.

He recently said, "I am pleased that many teams follow me, but I want to demonstrate on the field that I am at the level of the greatest and I want to show it in the future."