TIMELINE: Zapatero as Spanish prime minister

(Reuters) - Jose Luis Rodriguez Zapatero is hoping to achieve a second term as Spanish prime minister in a parliamentary election on Sunday.

A darkening economic outlook and the end of a housing boom have set the stage for a close race.

Here is a short chronology of events in Spain since 2004:

March 11, 2004 - Ten bombs kill 191 people and wound hundreds in simultaneous explosions on the Madrid railways.

March 12 - Prime Minister Jose Maria Aznar links the Basque separatist group ETA to the attacks.

March 14 - A video tape purportedly from al Qaeda says it bombed the trains in retaliation for Spain's cooperation with U.S. President George W. Bush and his allies in the war in Iraq.

-- Spaniards throw out Aznar's centre-right government in a spectacular election upset. Socialist leader Jose Luis Rodriguez Zapatero becomes prime minister in April.

April 3 - Seven men including two suspected ringleaders of the bombings blow themselves up in an apartment in a suburb of Madrid as police close in. All are believed to be Arabs.

May 21 - The last Spanish troops leave Iraq. The pullout fulfils an election pledge by Zapatero, who opposed the Iraq war and branded the occupation "a fiasco".

October 10 - Zapatero appeals to ETA to give up the fight after the arrest of its suspected leader, Mikel Albisu Iriarte, alias "Mikel Antza".

February 2005 - Spain's parliament rejects Basque premier Juan Jose Ibarretxe's plan for virtual Basque independence.

June 30 - Spain approves a law legalizing gay marriage, despite rejection in the upper house and fierce opposition from the Roman Catholic Church.

January 31/February 1, 2006 - Zapatero becomes the first prime minister in 25 years to officially tour Melilla and Ceuta, two Spanish enclaves on Morocco's Mediterranean coast that Morocco claims as its own. They hit the headlines in October 2005 when African migrants tried to storm fences in a bid to reach Europe.

March 22 - ETA declares a "permanent ceasefire".

December 30 - Hundreds of thousands protest in Madrid against the Socialists' liberalization of laws on divorce and abortion.

December 30 - A car bomb explodes at Madrid's airport, killing two people and forcing Zapatero to break off a peace process with ETA.