GLOBAL MARKETS-US, European shares up after China stimulus but Greece weighs

* Updates with U.S. markets, changes byline, dateline, previous LONDON

* European shares rise on telecoms sector bid

* Wall St opens higher after sharp decline Friday

* Euro slips on Greece worries, dollar

* Asian shares fall as China stimulus fails to lift mood

By Sinead Carew

NEW YORK, April 20 (Reuters) - European and U.S. stocks rose on Monday after China announced economic stimulus measures while the euro fell against the dollar on worries Greece may default.

Wall Street reversed course after falling steeply on Friday, as companies reported good quarterly earnings although without enough strength to push stocks to record highs.

A hefty cut announced on Sunday in the amount of cash Chinese banks must keep in reserves aimed at boosting lending initially lifted shares in China and Japan but both gave up their gains to end lower as investors focused on new Chinese stock trading regulations unveiled last week.

"What's helped the market today is the story about more stimulus in China," said Rick Meckler, President of LibertyView Capital Management in Jersey City, New Jersey.

But the downside, he said, is that the stimulus is a response to a stubborn lack of growth and concerns remain about currency effects and Greece.

"These have kept the market very range bound and we just keep climbing, falling, and starting to climb back up again."

The Dow Jones industrial average jumped 226.48 points, or 1.27 percent, to 18,052.78, the S&P 500 gained 19.09 points, or 0.92 percent, to 2,100.27 and the Nasdaq Composite added 45.21 points, or 0.92 percent, to 4,977.03.

The euro fell 0.65 percent against the dollar to $1.0736 after IMF and G20 meetings in Washington generated no progress on prospects of Greece reaching a deal on financial aid that would keep it afloat and in the euro zone.

The dollar was up 0.4 percent against a basket of other major currencies.

"We see the dollar moving towards parity with the euro in the third quarter, but if something happens around Greece, it may come sooner," said Lee Hardman, a strategist with Bank of Tokyo-Mitsubishi UFJ in London.

The pan-European FTSEurofirst 300 stocks index was up 0.9 percent at 1,621.52, boosted by a 1.3 billion euro bid by Telenet (Other OTC: TLGHY - news) for Dutch KPN's mobile telephony unit in Belgium.

MSCI (NYSE: MSCI - news) 's broadest index of Asia-Pacific shares outside Japan fell 1.2 percent while Tokyo's Nikkei lost 0.1 percent.

Chinese shares erased gains as fears of a regulatory crackdown offset the central bank measures. The CSI300 index of the largest listed companies in Shanghai and Shenzhen fell 1.6 percent.

Oil prices turned positive after falling when Saudi Oil Minister Ali al-Naimi said Saudi production would stay near record highs in April.

Brent crude reversed earlier losses to be up 0.1 percent at $63.49 a barrel after falling as low as $62.10 earlier in the session. It had hit a four-month high of $64.95 last week. U.S. crude was 1.2 percent at $56.40. (Additional reporting by Rodrigo Campos in New York, Francesco Canepa and Patrick Graham in London and Lisa Twaronite in Tokyo; Editing by James Dalgleish)