TOKYO, Sept. 23 — Yasuo Fukuda, a mild-mannered moderate known for his ability to build consensus behind the scenes, was chosen Sunday by Japan's governing Liberal Democratic Party to become the country's next prime minister. Facing one of their deepest crises in a half-century of power, Liberal Democrats decided on Mr. Fukuda, 71, to steady a party wobbling from Prime Minister Shinzo Abe's disastrous one-year government, his abrupt resignation 11 days ago and a surging opposition. Mr. Fukuda, sometimes described as a foreign policy dove who has long emphasized the importance of building strong ties with China and the rest of Asia, represents a break from the nationalist Mr. Abe and his predecessor, Junichiro Koizumi. At home, analysts say, Mr. Fukuda will be pressed to slow down the political and economic reforms undertaken by Mr. Koizumi that had angered the party's base.