Mikio Aoki, secretary general of the Liberal Democratic Party's Upper House caucus, was promoted Monday without opposition to the position of caucus chairman.

Aoki, 70, responsible for the LDP's campaign in the July 11 House of Councilors election, was promoted despite the party's disappointing result at the polls.

As a recent change in party rules means he will serve as chairman for three years, he could be the key LDP person in the next triennial Upper House election.