Avram Grant has resigned as manager of Portsmouth, but is odds-on favourite to take charge at West Ham.

Grant, 55, announced his decision to leave the beaten FA Cup finalists in an open letter to fans on the club's website.

"This was one of the most difficult decisions I've had to take in my football career," said Grant who took over at Fratton Park last November.

Grant arrived as Portsmouth's director of football in October 2009 but replaced Paul Hart as manager the following month, with the club bottom of the league with just seven points from 13 games.

Crippled by financial problems, the club went into administration in February and were subsequently deducted nine points by the Premier League - a punishment that all but condemned them to relegation.

They went on to finish bottom of the table on 19 points but reached the FA Cup final, losing the Wembley showpiece 1-0 to Grant's former club Chelsea.

"After a lot of soul searching and under the circumstances, I'm taking a different direction," explained Grant, who won 10, lost 16 and drew seven of his 33 matches in charge.

"Portsmouth has given me a feeling of home away from home. I might be leaving Portsmouth physically, but you cannot take Portsmouth away from me and my heart.

"It's been both a difficult and complex year for us at the club, but, at the same time, it's been a wonderful and uplifting professional and personal experience.

"I have been inundated with letters and emails from fans. Many have brought tears to my eyes - and, take it from me, it takes a lot to do that.

"I will never forget you, the loyal fans of Pompey, who, without a doubt, helped me protect the team under such complex circumstances.

"There are very few teams in the world that have fans as passionate and devoted as you are. Seeing you all so proud with your heads held up high is the best reward I can receive.

"I can never fully repay the faith and backing I got from the fans, players and staff who gave a hundred per cent. I truly thank you all for granting me the opportunity and the privilege to be part of your special city and unique club.

Portsmouth consultant Peter Storrie was full of praise for the work of Grant. "I think Avram has done such a fantastic job down here. I am sure there are a lot of clubs interested in him and rightly so because he has shown everyone what a very, very good manager he is and how well he works with players."

Fans were quick to comment on the Portsmouth forum:

"Good luck Avram, you were superb. So dignified. Thanks for the memories, beating Redknapp at Wembley are memories I will treasure forever."

"Great open letter to fans shows class and dignity of the man."

"I'm so disappointed, I really really liked him. He loved the club, he stuck with us. I'm going to miss him alot. AVRAM YOU'RE A LEGEND thank you for keeping the boat afloat."

One from sender Southport PFC said: " To me Avram's commitment was what made this season special - perhaps more so than some of the seasons we stayed up. Yep we've gone down etc, but he got the passion and belief going with less than adequate resources. To me that counts more than winning things. Football is about fans not just a business - he recognised that.

"For fans who want to win every week clap politely and glory hunt go watch Man U, Chelsea, Liverpool, Arsenal etc - you get the return you deserve - the real fans at those clubs are realising how short changed they really are.

"Avram recognised real character and the real passion real Pompey fans have for the club.

"He's given the authorities a great big V sign to their conventional money grabbing thinking (whatever he does next he made a stand) and that's what's great about him. Give him freedom of the city - he's the recent manager who really deserves it."