Rishi Sunak received the most votes, just as in the previous two votes.
He is a former finance minister in Boris Johnson's government and was one of the first to announce his resignation in protest of the prime minister's leadership.
He has previously been in bad weather because his wife has used loopholes to avoid taxes.
Penny Mordaunt knocked out
Liz Truss has previously been described as "a real Tory" by James Savage, editor-in-chief of The Local, as she advocates lower taxes and less regulation, among other things.
If Truss wins the final round, she will be the third woman in the post of Prime Minister, after Margaret Thatcher and Theresa May.
The third candidate who remained until Wednesday was Penny Mordaunt.
She is Deputy Minister of Trade, has been described as "vague" in the British media and has, among other things, proposed a project to compose a new British signature tune, according to The Guardian.
So now she is voted out.
Rishi Sunak received 137 votes, Liz Truss 113 and Penny Mordaunt 105, writes BBC.
Tories members vote in the final round
A final vote, conducted by the Tories' 160,000 members, is now awaited on who will take over as party leader for the Tories - and thus the Prime Minister of the United Kingdom.
Whether it will be Sunak or Truss who takes over after Boris Johnson will be announced on 5 September.