Nyamira Senator Kennedy Mong'are has opted out of the presidential race five months after launching his bid.
Sources said the Senator was yet to raise the signatures from 2,000 unaligned voters across 24 counties.
Mong'are had declared he would be vying for the presidency through the
Federal Party of Kenya.
His decision to run, he said, was to free Kenyans from the "betrayal of post-independence regimes."
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"We need a paradigm shift in our politics," Mong'are told journalists in an earlier briefing.
"My opponents should be careful. They can ignore me at their own peril. Kenya needs change and I am that change."
He becomes the second to quit the race after Pete Ondeng who said the race is crowded.
"A crowded race of 18 candidates seeking election as president will not be fair," the economic development expert said on Monday.
Ondeng', who was sponsored by the Restore and Build Kenya party, has endorsed Joe Nyagah who is running as an independent.
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The candidates were cleared by the Registrar of Political Parties to seek the presidency.
The development means President Uhuru Kenyatta (Jubilee Party) will face off with 15 candidates in the August poll.
His closest contestant is NASA co-principal Raila Odinga. His running mate is Wiper leader Kalonzo Musyoka.
There are 14 other candidates in the race, 11 of which are running as independents while the rest are sponsored by various parties.
They include Professor Michael Wainaina - PhD, Abduba Dida (Tunza Coalition), and Ekuru Aukot (Thirdway Alliance Party).
Nazlin Omar (Independent Presidential Candidate) and Cyrus Jirongo (UDP Party) are also in the list.
David Munga, Stephen Oweke Oganga, Robert Mukwana Juma, Joseph Ngacha, Japheth Kavinga, Nixon Kukubah, Joseph Musyoka and Erastus Nyamera were also cleared to vie.
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