UPDATE 1-Gamesa, Iberdrola set strategic alliance for 2011

* Gamesa, Iberdrola to manage wind farms separately to 2011

* Iberdrola could buy Gamesa's wind farms instead of JV

* Iberdrola will not buy Gamesa UK wind farms

* May include Gamesa UK wind farms in possible JV. (Adds changes to deal on UK, Dominican assets)

MADRID, Sept 23 (Reuters) - Spanish wind turbine maker Gamesa (GAM.MC) said on Wednesday a strategic agreement drawn up in June 2008 with renewables firm Iberdrola Renovables IBR.MC will not come into effect before June 30, 2011.

The agreement, whereby Gamesa will swap a European portfolio of wind farms in exchange for a stake in a joint venture managing the assets with Renovables, now gives the wind power generator the option to acquire the assets without creating the joint venture, Gamesa said in a statement.

"The strategic agreement ... has been adapted to market conditions and enables the deal to overcome legal problems which affected its execution under the original terms," Gamesa said.

Renovables will not buy Gamesa's wind farms in the Dominican Republic or the UK as originally agreed but will include the UK assets in the potential wind farm joint venture, extending a deal originally intended solely for Continental Europe.

If Iberdrola decides to form the joint venture with Gamesa, it will take a 75 percent stake in the company, with Gamesa holding the remainder. (Reporting by Jonathan Gleave; Editing by Greg Mahlich)