GLOBAL ECONOMY-China, U.S. factory data improves, global risks remain

* Chinese manufacturing expands, economy gaining momentum

* U.S. PMI shows quickest growth in eight months

* Euro zone Composite PMI below 50 but at nine-month high

* European malaise, U.S. fiscal cliff worries sap sentiment

By Steven C. Johnson

NEW YORK, Dec 14 (Reuters) - China's vast manufacturing

sector grew in early December and U.S. factories were having

their best month since April, surveys showed on Friday, adding

to hopes that the world's top two economies were on the mend.

Solid growth from the United States and China will be

crucial to reviving the world economy in 2013, particularly with

the euro zone likely sliding deeper into recession.

A possible budget crisis in the United States at year-end

tempered investor optimism, however, and added a big dose of

uncertainty to the economic outlook for the year ahead.

Investors and economists fear the United States could fall

back into recession if lawmakers can't strike a deal to avert

the "fiscal cliff" and allow some $600 billion in automatic tax

hikes and spending cuts to take effect in 2013.

That's a grim prospect for global growth, particularly since

the 17-country euro zone is already in recession. While an index

of euro zone manufacturing and service sector activity rose to a

nine-month high this month, it still showed contraction in both

areas. That's consistent with the economy shrinking by 0.5

percent in the fourth quarter.

The news was better in Asia. The HSBC flash PMI showed

China's manufacturing sector expanded in December at its fastest

pace in 14 months as new orders and employment rose, adding to

evidence of a pick-up in the economy that helped lift sentiment.

The data was "a further sign that the Chinese economy is

already starting to recover," said Nikolaus Keis at UniCredit.

In the United States, financial information firm Markit said

its manufacturing index showed the sector grew at its quickest

pace in eight months as demand from domestic and foreign

customers increased. [ID: nL1E8ND8QB]

Separate data showed factory output posting its sharpest

increase in nearly a year in November as auto production

rebounded.

Stronger manufacturing should help bolster a U.S. economy

that has seen slow but steady improvement in employment and

consumer spending and signs of life in the housing market.

"People are always hoping for good news from the United

States and China, as both economies are the main drivers of

global economic activity," said Tom Porcelli, chief U.S.

economist at RBC Capital Markets.

However, he said a more closely watched gauge of U.S.

factory activity published earlier this month by the Institute

of Supply Management showed the sector shrank in November,

making it premature to conclude manufacturing was improving.

Uncertainty about the fiscal cliff also hurt sentiment, and

not just because lawmakers are seen as increasingly unlikely to

strike a deal by year-end.

More troubling, said Lena Komileva, chief economist at G+

Economics in London, is that there is no sign Congress is ready

to draft a long-term deal to reduce the U.S. deficit, which was

set to exceed $1 trillion in 2012 for the fourth straight year.

If lawmakers move from "short-term compromise to short-term

compromise," she said that raises "the possibility of a series

of fiscal cliffs in which harder compromises are left to future

negotiations, and we'll see recurring damage to economic

confidence."

EURO ZONE IMPROVES SLIGHTLY

Earlier on Friday, composite PMI data from Germany, Europe's

largest economy, showed its private sector bounced back to

growth for the first time in eight months in December.

In France, the downturn eased but the PMI held below 50 for

the 10th straight month, indicating contraction.

But the regional euro zone PMI has been below the 50 mark

for all but one of the past 16 months.

The PMI for the euro zone's dominant service sector

continued to shrink this month, though at a slightly slower

pace, as firms cut prices even as costs rose, taking a hit on

their profit margins for a ninth straight month.

Manufacturers, who led the bloc out of the last recession,

fared little better. The factory PMI crept up to 46.3 from 46.2.

But in a sign the global economy might be improving, the

rate of decline in new export orders from factories eased, with

the sub-index at a nine-month high of 46.8.

"There are some rays of hope here. It is moving in the right

direction so there are signs that the business cycle has reached

a low point globally and is picking up," said Chris Williamson,

chief economist at Markit.

The euro zone economy contracted 0.2 percent in the second

quarter and 0.1 percent in the third, meeting the technical

definition of a recession and a Reuters poll last week predicted

a 0.3 percent contraction in the current period.

That would be slightly better than the PMIs published on

Friday suggest.