London - Marco Silva resigned as manager of relegated Premier League side Hull on Thursday, the club announced.
The 39-year-old Portuguese -- who Jose Mourinho once described as his 'kid friend' -- impressed during his stay reviving the club's hopes of preserving their top-flight status after taking over in January with them in a desperate state at the foot of the table.
He succeeded in lifting them out of the bottom three but a Swansea revival saw them survive and Hull's relegation confirmed on the penultimate weekend of the season.
"Marco was offered the opportunity to continue the work he has done in the four-and-a-half months he has been at the KCOM Stadium," read the club statement.
"Unfortunately, after considering his future, he has chosen to leave in order to further his career.
"Although disappointed by Marco's departure, we would once again like to place on record our appreciation of his efforts and those of his support staff.
"Despite only being in charge for a short period of time, the 39-year-old became a firm fans' favourite and will be forever remembered for his efforts to maintain our Premier League status."
Silva, who coached Olympiakos to the Greek title in the 2015/16 campaign, has left with all his backroom staff.
He is rumoured to have held talks with Portuguese giants Porto this week -- who parted company with Nuno Espirito Santo on Monday and are desperate to end their four-year trophy drought.
However, there has been plenty of money bet on him filling the vacancy at Premier League side Crystal Palace following Tuesday's resignation of Sam Allardyce.
Hull, who have been beset by problems with a proposed sale by ailing owner Assem Allam to a Chinese bid falling through last year and little or no money made available for buying players even before Silva arrived, for their part said they would 'undertake a thorough and considered recruitment process to appoint a replacement'.