* GDP seen up 0.5-1.0 pct in 2009, 0.5-1.3 pct in 2010
* Preliminary 2010 average inflation forecast at 1.5-1.9 pct
* Budget may be revised in July (Adds details, finance minister on budget revision)
WARSAW, May 5 (Reuters) - The Polish government will cut its 2009 economic growth forecast to 0.5-1.0 percent from 1.7 percent at its meeting later on Tuesday, two government sources told Reuters.
The cabinet will also approve the finance ministry's preliminary forecast for next year's gross domestic product growth of 0.5-1.3 percent and average annual inflation of 1.5-1.9 percent, the officials said.
On Monday, Finance Minister Jacek Rostowski dismissed European Commission's forecast that the economy of the European Union's largest ex-communist member will contract 1.4 percent this year.
Analysts in a recent Reuters poll predicted that the Polish economy will grow 0.8 percent this year, slowing sharply from 4.9 percent growth in 2008.
However, the International Monetary Fund and a growing number of economists, including the EU executive, now expect Poland's economy to contract, along with other countries in the once-booming region of central and eastern Europe.
Rostowski told the Dziennik daily Poland may revise its 2009 budget in July, if needed. (Reporting by Pawel Sobczak and Gabriela Baczynska; Writing by Chris Borowski; Editing by Tomasz Janowski)