New Delhi, Dec 22 (PTI): In a sudden move, Delhi Lt Governor Najeeb Jung resigned today, ending a nearly three-and-half- year-long eventful tenure, mostly marked by bitter confrontation with AAP government on a range of issues that virtually brought governance to a halt on many occasions.

Without citing reasons for the decision, 65-year-old Jung, who had taken charge in July 2013, thanked Prime Minister Narendra Modi for his help and cooperation and Chief Minister Arvind Kejriwal for his "association".

In a brief statement, Jung''s office said he has submitted his resignation to the Government of India and that he would be returning back to academics, "his first love".

Sources close to him told PTI that his resignation has nothing to do with his acrimonious relationship with the AAP government and he was contemplating to quit for last few months.

"His decision to quit was not at all related to his relationship with the AAP government. It was purely a personal decision which he was mulling over for quite some time," they said.

Reacting to Jung''s resignation, Kejriwal said the decision surprised him. "Sh Jung''s resignation is a surprise to me. My best wishes in all his future endeavours," he tweeted.

While BJP was guarded in its reaction, Congress said the Centre must explain why Jung was "unceremoniously removed and whether it was done to bring someone to the top administrative post who is ideologically close to the RSS."

Deputy Chief Minister Manish Sisodia said despite several "bitter-sweet experiences, I can say that we have worked very well for Delhi with Jung. Good wishes for his future."

A 1973-batch IAS officer, Jung had assumed charge as 19th Lt Governor of Delhi on July 9, 2013, five months before the Delhi Assembly elections.

The then Chief Minister Sheila Dikshit had played a role in appointing Jung, who was serving as Vice Chancellor of Jamia Millia University, to the top post in the city administration.

He had run the city for nearly one year after the AAP government had quit on February 14, 2014 after a short stint of 49 days.

In the statement, his office also said "Jung also thanks the people of Delhi for all their support and affection, especially during the one year of President''s Rule in Delhi, when he got unstinted support from them and which in turn helped run the administration in Delhi smoothly and effortlessly."

Normally governors are appointed for a five-year term but there is no fixed tenure for the Lt Governors. Union Home Secretary Rajiv Mehrishi said he came to know about Jung''s resignation from the media.

"The LG met me day before yesterday but he did not give any indication of submitting his resignation. Another meeting of mine with the LG is scheduled for tomorrow...I have come to know about his resignation only from the media," he said.

Born on January 18, 1951 Jung has done his post graduation in History from Delhi University and later did MA in Social Policy and Planning from London School of Economics, UK.

He had joined Indian Administrative Services (IAS) in 1973 and served in Madhya Pradesh government and at several key positions, including as joint secretary in the ministry of petroleum and natural gas, in the central government.

A literary enthusiast, Jung had also worked with the Asian Development Bank (ADB) and the Oxford Institute for Energy Studies of Oxford University on Energy related issues.

BJP leader RPN Singh said, "He did a good job and was performing on ground. He must have thought of something."

Delhi Congress Chief Ajay Maken alleged that Jung was unceremoniously removed and demanded that the Centre make public reasons behind the decision.

"Was he removed to bring someone who is close to RSS? Was it done considering the upcoming municipal polls? Jung is an able administrator," he said.

Congress leader P C Chacko said BJP''s attitude towards Governors and LGs may be the reason behind Jung''s decision.

"BJP never takes independent stand as per as the offices of Governors and LGs are concerned. BJP wants the Governors and LGs to act as per their political thinking. This is putting many Governors and LGs in difficulties. May be this is behind the resignation," he said.

The AAP alleged Jung worked under the "influence" of Modi dispensation and questioned whether the power tussle between the Centre and Delhi government will continue even after the appointment of a new LG.

"Modi government promotes its people. We hope he gets a better posting after this. I am unhappy that his tenure was disgraceful. Now that he has gone, good luck to him.

"Najeeb Jung''s behavior was not his. He was under the influence of someone. We hope the next LG gives priority to issues concerning people and does not work under anyone''s influence," AAP''s Kumar Vishwas said.