* MSCI Asia ex-Japan tumbles, Nikkei retreats from 33-month highs

* Euro pressured by worries over euro zone political jitters

* Yen takes a breather from selling but still on weakening trend

* Reserve Bank of Australia keeps rates unchanged as expected

* European shares seen little changed

By Chikako Mogi

TOKYO, Feb 5 (Reuters) - Asian shares, oil and the euro fell on Tuesday as investors took profits from recent rallies, while the yen got a respite from broad-based selling.

European markets are seen barely changed, with financial spreadbetters predicting London's FTSE 100, Paris's CAC-40 and Frankfurt's DAX would open up nearly flat. But a 0.1 percent gain in U.S. stock futures suggested a firm open on Wall Street.

The MSCI's broadest index of Asia-Pacific shares outside Japan tumbled 0.9 percent, dragged lower by a steep 1.7 percent fall in Hong Kong shares. The pan-Asian index climbed to a 18-month high on Monday.

Japan's benchmark Nikkei stock average closed down 1.9 percent, after scaling a 33-month high on Monday.

Positive data from China failed to brighten the bearish mood, after the Standard & Poor's 500 Index had its worst day since November on Monday on discouraging U.S. factory orders and worries that a potential political shake-up could disrupt the euro zone's efforts to resolve its debt crisis.

Analysts and traders said selling was a correction to markets rallying on receding tail risks such as growing euro zone stability and an improving global economic outlook, while global monetary easing still underpinned sentiment.

"This move in equities ... looks to be a healthy correction, nothing more," said Richard Yetsenga, Head of Global Markets at ANZ Research, adding that downside risk would likely convince major central banks globally to stick to easy policy.

In China, the HSBC services purchasing managers' index rose to a four-month high of 54 in January from December's 51.7, underlining confidence in the world's second-biggest economy, which is expected to grow 8.1 percent this year, off a 13-year low of 7.8 percent hit in 2012.

"The data globally is unquestionably better but the recovery still seems gradual. (China) hit the bottom and they had a bit of a bounce but nothing much else happened. We don't really seem to have preconditions for a much stronger bounce than that (8 percent growth)," Yetsenga said.

The Australian dollar fell 0.3 percent to $1.0405 after the Reserve Bank of Australia kept its cash rate steady at 3.0 percent, as expected, having just cut in December. Australian shares fell 0.5 percent but trimmed some earlier losses after the RBA's rate decision.

The euro took the brunt of renewed focus on the euro zone problems, having risen 2.3 percent so far this year against the U.S. dollar, up about 5.4 percent against sterling and 1.8 percent higher against the Australian dollar.

The euro eased 0.2 percent to $1.3485, retreating further from Friday's 14-1/2-month peak of $1.3711, ahead of the European Central Bank's policy meeting on Thursday.

"Markets have been increasingly comfortable with European risks over the past few months and are largely not positioned for this increase in political problems. The outcomes in Spain and Italy are far from certain and may represent stumbling blocks for further expansion in risk appetite," Barclays Capital said in a research note.

Spain's opposition party on Sunday called for Prime Minister Mariano Rajoy to resign over corruption allegations, which Rajoy denies, pushing Spanish 10-year bond yields to six-week highs.

In Italy, 10-year Italian government bond yields hit their highest since late December, as chances of former prime minister Silvio Berlusconi regaining power raised worries about Rome's ability to fix its fiscal problems.

The yen took a breather, firming from lows against a broad range of currencies.

The dollar steadied at 92.36 yen after scaling its highest since May 2010 of 93.185 on Monday, while the euro eased 0.1 percent to 124.53 yen, off its loftiest since April 2010 of 126.97 hit on Friday.

"Markets are broadly undergoing a correction and the euro is definitely facing profit-taking, given the pace of its climb. Worries about the euro zone debt crisis always remain a downside risk for the euro, and could push it lower to $1.32-$1.33," said Hiroshi Maeba, head of FX trading Japan at UBS in Tokyo. "But the trend is still upward for dollar/yen, cross/yen. The dollar could reach 95 yen by the end of the month."

As long as markets hold out expectations for the Bank of Japan to implement aggressive monetary easing to beat decades of deflation in Japan, the yen will stay pressured. Any correction to the dollar's rise against the yen was also be seen as shallow, with many traders and analysts seeing a firm floor around 87-88 yen.

Asian credit markets faltered with the plunge in equities, widening the spread on the iTraxx Asia ex-Japan investment-grade index by three basis points.

Brent crude slipped towards $115 per barrel, giving up some of its gains from the last three weeks, on renewed euro zone worries and a slightly firmer dollar.