By Mehreen Zahra-Malik

ISLAMABAD (Reuters) - Pakistan's Supreme Court sacked the head of the state-run anti-corruption agency on Tuesday because of his faulty selection, officials said, a move likely to slow down an already shoddy accountability process.

The leader of the opposition filed a petition against Fasih Bokhari's appointment as chairman of the National Accountability Bureau (NAB) in October 2011, saying he had not been consulted as required by law.

The Supreme Court ruled that Bokhari's selection was in violation of the constitution.

"The chairman is not happy with the Supreme Court's decision, but he has accepted it and is going home," a NAB official said, requesting anonymity.

The sacking may slow down the accountability process, given that a new government that emerged from a May 11 election will have to be sworn in and fresh consultations held between the government and the opposition before a new NAB chairman can be appointed.

"As per the law, NAB cannot take decisions on any pending cases unless the chairman signs off on them," said Ahmed Safdar, a bureau spokesperson.

"For all practical purposes then, we can't move forward on any cases until we have a new head, which will take some time."

The agency is investigating several high-profile cases, including charges against former Prime Minister Raja Pervez Ashraf on suspicion of receiving kickbacks in power projects and three accusations of graft against Prime Minister-elect Nawaz Sharif.

Both men deny any wrongdoing.

(Editing by Nick Macfie and Robert Birsel)