* Abe promises aggressive monetary, fiscal policies
* Yen hits 20-month low on "Abenomics" expecations
* Cabinet line-up expected 0700 GMT: lots of allies, leaning right
The lower house of Japan's parliament approved Shinzo Abe as prime minister on Wednesday, giving the hawkish lawmaker a second chance at the top job as the country battles deflation and confronts a rising China.
Abe, 58, has promised aggressive monetary easing by the Bank of Japan and big fiscal spending by the debt-laden government to slay deflation and weaken the yen to make Japanese exports more competitive.
The grandson of a former prime minister, Abe has staged a stunning comeback five years after abruptly resigning as premier in the wake of a one-year term troubled partly by scandals in his cabinet and public outrage over lost pension records.
His Liberal Democratic Party (LDP) surged back to power in this month's election, three years after a crushing defeat at the hands of the novice Democratic Party of Japan.
"I want to learn from the experience of my previous administration, including the setbacks, and aim for a stable government," Abe told reporters before the lower house voted him in as Japan's seventh prime minister in six years.
Abe looks set to pick a cabinet of close allies leavened by some LDP rivals to fend off the criticism of cronyism that dogged his first administration. The line-up will be announced around 0700 GMT.
Japanese media have said Abe will name former prime minister Taro Aso, 72, as finance minister, ex-trade and industry minister Akira Amari as minister in charge of a new economic revival headquarters and policy veteran Toshimitsu Motegi as trade minister. Motegi will also be tasked with formulating energy policy in the aftermath of the Fukushima nuclear disaster last year.
Loyal Abe backer Yoshihide Suga is expected to become chief cabinet secretary, a key post combining the job of top government spokesman with responsibility for coordinating among ministries.
Others who share Abe's agenda to revise the pacifist constitution and rewrite Japan's wartime history with a less apologetic tone have also been floated for posts.
"These are really LDP right-wingers and close friends of Abe," said Sophia University professor Koichi Nakano. "It really doesn't look very fresh at all."
CHINA TIES, JULY ELECTION
The yen has weakened about 9.8 percent against the dollar since Abe was elected LDP leader in September. On Wednesday, it hit a 20-month low of 85.38 yen against the greenback on expectations of aggressive monetary policy easing.
Abe has threatened to revise a law guaranteeing the Bank of Japan's (BOJ) independence if it refuses to set a 2 percent inflation target.
BOJ minutes released on Wednesday showed the central bank was already pondering policy options in November, concerned about looming risks to the economy. The BOJ stood pat at its November rate review meeting but eased this month in response to intensifying pressure from Abe.
Abe also promised during the election campaign to take a tough stance in territorial rows with China and South Korea over separate chains of tiny islands, while placing priority on strengthening Japan's alliance with the United States.
Japanese media said Abe would appoint two low-profile officials to the foreign and defence portfolios.
Itsunori Onodera, 52, who was senior vice foreign minister in Abe's first cabinet, will become defence minister while Fumio Kishida, 55, a former state minister for issues related to Okinawa island - host to the bulk of U.S. forces in Japan - will be appointed to the top diplomatic post, the reports said.
Abe, who hails from a wealthy political family, made his first overseas visit to China to repair chilly ties when he took office in 2006, but has said his first trip this time will be to the United States.
He may, however, put contentious issues that could upset key trade partner China and fellow-U.S. ally South Korea on the backburner to concentrate on boosting the economy, now in its fourth recession since 2000, ahead of an election for parliament's upper house in July.
The LDP and its small ally, the New Komeito party, won a two-thirds majority in the 480-seat lower house in the Dec. 16 election. That allows the lower house to enact bills rejected by the upper house, where the LDP-led block lacks a majority.
But the process is cumbersome, so the LDP is keen to win a majority in the upper house to end the parliamentary deadlock that has plagued successive governments since 2007.
"The LDP is still under the critical eyes of the public. We need to earn their trust by get things done one by one," Abe told party lawmakers ahead of the lower house vote.
"First on the agenda is economic recovery, beating deflation and correcting a firm yen and getting the economy back on the growth path. If we don't pursue this target, an upper house election next year will be a tough one for us."