* Poland's manufacturing sector contracts for the second straight month in June.
* Czech expansion slows for third consecutive month, export growth remains close to May's 35-month low.
By Michael Winfrey
PRAGUE, July 1 (Reuters) - The global economic slowdown tightened its grip on Eastern Europe in June, data showed on Tuesday, as strong currencies and weak euro zone demand put the squeeze on manufacturing, the engine of the region's growth.
Two of the biggest emerging economies in the European Union tracked the euro zone's first contraction in three years, with Poland shrinking for the second straight month in June and the Czechs showing their third deceleration in growth. The RBS/Markit Polish Purchasing Managers Index survey <PLPMI=ECI> showed a drop to 47.9, versus 49.3 in May. It was below the 50 mark that indicates a contraction in production from the previous month.
New orders fell to 47.2 and output fell to 48.1 points. Czech PMI <CZPMI=ECI> slipped to 50.7, the weakest rate of expansion since a growth period began in October, 2002.
"The manufacturing sector is clearly signalling the good times are over and the slowdown is taking place," said Raffaella Tenconi, an economist at Dresdner Kleinwort in London.
"The rest of the economy tends to be in better shape, but the moderation in exports will eventually feed through to them too. Consumer sentiment is cooling rapidly in the Czech Republic and it has begun to weaken in Poland."
EXPORTS SUFFER
PMI in the euro zone, which is eastern Europe's main destination for exports, dropped to 49.2 in June, the first contraction since June 2005.
Manufacturing in the EU's 12 mostly ex-communist newcomers closely track the euro zone, and whenever demand falls in the West, its impact is felt in industry in Poland, Hungary, Slovakia and the Czech Republic.
That was nowhere more clear than in Poland, where export orders showed their biggest fall in almost seven years in June, dropping to 43.2, from 46.9 in May.
The survey said firms linked the fall to the strong zloty <EURPLN=>, which has gained about 30 percent since Poland joined the European Union in 2004 and 7.1 percent this year, and the euro zone slowdown.
The Czechs, too, have cited their crown currency <EURCZK=>, as a dampening factor on exports which, similar to orders from domestic consumers, remained close to a 35-month low hit in May.
The crown is near all time highs of 23.82 per euro. It has firmed around 17 percent to the euro in the past year and 9.4 percent since the start of 2008.
"The currency appreciation will continue to hit export numbers in these countries I think for a good few months," said Debbie Orgill, a senior economist at ABN Amro, which presents the data.
Still, in both countries strong currencies have helped fight a surge in prices driven by steadily growing domestic demand and spiking global commodity costs which, for the Czechs, pushed up input prices at the fastest rate since March.
Poland's central bank hiked interest rates to 6.0 last week to combat inflation which has tracked global price growth higher and was near a four year high of 4.4 percent in May.
The Czechs held the cost of borrowing steady at 3.75 percent, or 25 basis points lower than the euro zone, last week, helped by the strong crown currency.
But analysts said an expected rate hike by the European Central Bank this week may make the crown less attractive, while persistently high inflation -- the central bank said it could hit 7 percent this summer -- could prompt higher interest rates.
"The fact that the exchange rate is cited as a key cause of weaker export demand could signal some slowing in the rate of appreciation," Orgill said of the Czechs.
"Price components moved higher, which could add to the cause for a near-term interest rate hike.