* Dutchman throws his support behind Jordan's Prince Ali
* Election takes place in Zurich on May 29 (Adds background)
AMSTERDAM, May 21 (Reuters) - FIFA presidential candidate Michael van Praag has withdrawn from next week's election and thrown his weight behind Prince Ali Bin Al Hussein, he said on Thursday.
"Michael van Praag decided to withdraw his candidacy to become the next FIFA president and to join forces with presidential candidate Prince Ali Al Hussein," said a statement published by his campaign organisers on Thursday.
The Dutch FA president added that he had made the decision after "thorough deliberation and reflection with different involved parties and stakeholders" and would hold a news conference later on Thursday.
Van Praag's announcement has left Jordan's Prince Ali and former Portugal international Luis Figo as the only challengers to incumbent Sepp Blatter.
The announcement meant the spotlight switched to Figo.
The former Portugal forward's spokesman was not immediately available for comment, although on Wednesday had denied suggestions that the 42-year-old would also pull out.
"Luis is an independent candidate and he will keep being independent. He will not travel to Holland, contrary to what the rumours say," the spokesman told Reuters.
Blatter, 79, is runaway favourite to secure a fifth mandate at the election in Zurich on May 29, where each of FIFA's 209 member associations holds one vote.
Of Blatter's three challengers, Van Praag was the most outspoken critic of the Swiss administrator.
In March, he told UEFA's Congress that Blatter's opponents had a responsibility to "clean up the mess" and that the "beautiful heritage of international football has been tarnished" by allegations of corruption. (Writing by Brian Homewood in Berne; Editing by John O'Brien and Ken Ferris)