"The UEFA executive committee has decided to give its unanimous support to Mr Joseph S Blatter in the upcoming FIFA presidential elections and strongly recommends all UEFA member associations to do likewise," UEFA said in a statement on Friday.
The statement was signed by the 16 members of the executive committee of European football's ruling body.
Blatter will be up against Asian Football Confederation president Mohamed Bin Hammam of Qatar in the June 1 election and UEFA's announcement could potentially swing the vote in his favour.
UEFA holds 53 of the 208 FIFA votes - one for each member federation - which will decide the election although Bosnia are suspended and ineligible to vote.
Blatter has already been promised the unanimous support of South America, which has 10 votes, and is confident of winning another 35 votes from CONCACAF (the confederation for North and Central America and Caribbean football) which is expected to vote as a block.
Earlier this week, Blatter told the CONCACAF Congress in Miami: "I was not going to campaign here because at the beginning of congress the president of CONCACAF said: 'You don't need to campaign in this region'."
"The Americas in South America or CONCACAF have always been my base and I don't think that anything has changed especially after this congress and the declarations made at this congress."
NO CONFIRMATION
CONCACAF, however, has yet to confirm its support for the 75-year-old.
In an interview with the Frankfurter Allgemeine Zeitung in Germany one week ago, Blatter said he believed he also had about half the votes in Africa and Asia.
If his calculations are right, Blatter should win the contest easily.
Blatter, the eighth head of FIFA since world football's ruling body was founded in 1904, joined as a technical officer in 1975 and was general secretary from 1981-98 under the presidency of Joao Havelange.
In 1998 he swept to a 111-80 victory over Swede Lennart Johansson who conceded defeat, foregoing a second ballot.
Four years later Blatter claimed a landslide 139-56 victory over Cameroon's Issa Hayatou and, if anything, his grip on FIFA has tightened since then.
He had no opposition when he was re-elected in 2007.
Bin Hammam, 61, is also a candidate from within FIFA, having been a member of the powerful executive committee since 1996.
Although he was not part of the bidding team, he played a huge role when Qatar secured the rights in December to stage the 2022 World Cup finals.
