By Chao Deng 

The Chinese yuan held steady after the International Monetary Fund included the currency in its reserve basket, while most Asian shares rose amid optimism for stimulus from Europe's central bank later this week.

The stock gains also come after a flurry of private manufacturing gauges signaled continued slowdown in the region's factory activity, lifting hopes for easier monetary policies closer to home. China's official reading marked the fourth-straight month of contraction.

Earlier Tuesday, the People's Bank of China fixed the onshore yuan at the weakest level since late August, at 6.3973 to one U.S. dollar. The move comes after a widely expected decision by the IMF overnight to give the yuan reserve-currency status alongside the dollar, euro, pound and yen.

The onshore yuan, which can fluctuate 2% above or below the fixing, last traded at 6.3981, flat with its level late Monday in Asia.

The Shanghai Composite Index fell 0.4%.

Meanwhile, Hong Kong's Hang Seng Index rose 1.4%, Japan's Nikkei Stock Average rose 1%, Australia's S&P/ASX 200 gained 1.8% and South Korea's Kospi gained 1.3%.

The IMF's move, which marks a milestone in China's ascendancy as a global economic power, could help accelerate a mild pickup in international demand for the currency when it becomes effective late next year.

Still, the "decision does not imply immediate strengthening of the [yuan's] exchange rate," according to a report by ANZ Research.

Some investors say China's central bank may even relax its grip on the yuan's trading going forward. Officials "can afford to let [the yuan] go slightly wider or narrower [from their daily fixing] now that the IMF won't be scrutinizing them as the decision has been made," said Andrew Sullivan, managing director at Haitong Securities.

HSBC predicts that the onshore yuan will weaken by the end of the year to 6.50 to one U.S. dollar.

Traders said the central bank on Monday bought up the offshore yuan, which trades freely, through a large Chinese bank to narrow the gap between the currency and its onshore counterpart.

The offshore yuan last traded at 6.4288 against the U.S. dollar, 0.1% weaker than late Monday in Asia.

The weakening yuan also comes amid the most recent economic data signaling China's outlook remains murky. Earlier Tuesday, China said its official reading on factory activity for the month of November fell to 49.6, compared with 49.8 in October. A reading below 50 indicates contraction.

The Caixin China manufacturing purchasing managers index, a private gauge, rose to 48.6 in November from 48.3 in October.

The readings show China's manufacturing sector remains plagued by overcapacity, falling prices and weak demand. The dimming view casts doubt the world's second-largest economy can achieve its target growth of around 7%.

The PMI reading affirms "the view that the [People's Bank of China] is going to cut rates" as officials try to maintain that growth level, said Evan Lucas, market strategist at brokerage IG. The central bank has cut interest rates six times since last November.

Elsewhere, South Korea's Nikkei PMI stayed unchanged at 49.1 in November from a month earlier. Taiwan's rose to 49.5 in November from 47.8 in October.

In Australia, the sector expanded for the fifth straight month, with the Australian Industry Group Australian Performance of Manufacturing Index improving by 2.3 points to 52.5 in November.

Mr. Lucas added that much of the region's earlier stock gains come ahead of the European Central Bank's meeting Thursday, when many investors expect the bank to expand its quantitative easing program.

Meanwhile, the Reserve Bank of Australia isn't expected to move rates at its meeting Tuesday, although Michael McCarthy, chief market strategist at CMC Markets, said a shift in the bank's language toward easing would likely support shares and push the Australian dollar weaker. The local dollar was last up 0.1% at $0.7235.

The Australian banking sector led the benchmark higher Tuesday and materials stocks made more moderate gains, though iron ore tumbled to a fresh near-decade low. Spot iron ore fell 1.6% on Monday to $42.80 a ton, according to The Steel Index.

Declines in retail shares after the Black Friday holiday shopping weekend pressured U.S. stocks Monday. Early signs of spending showed brick-and-mortar stores faced difficulties.

Brent crude oil, the global benchmark, fell 0.4% to $44.78 a barrel. U.S. oil prices fell 0.1% on Monday after government data showed U.S. production is falling more slowly than expected.

Gold prices rose 0.6% at $1,071.40 a troy ounce.

Robb M. Stewart contributed to this article.

Write to Chao Deng at Chao.Deng@wsj.com

(END) Dow Jones Newswires

November 30, 2015 22:37 ET (03:37 GMT)