The European Tour has announced that the Portuguese Open is switching from April 1-4 to June 10-13.
The summer date became availabe on the 2010 Tour schedule after the Austrian Open was changed to September 16-19.
"The Estoril Open de Portugal is an important and long standing tournament on The European Tour and the extra time will guarantee that Europe's top players are presented with the best possible test," Manuel Agrellos, President of the Portuguese Golf Federation, said on the European Tour's website.
Irishman Michael Hoey defeated Gonzalo Fernandez-Castano in a play-off to win last year's Portuguese Open at Penha Longa near Lisbon.
Meanwhile, La Hipica, the course which staged the Madrid Open three years ago, has been confirmed as the venue for the Madrid Masters on May 27-30.