The Spanish international, who joined the Blues last summer from Atletico Bilbao for $15 million, left coach Jose Mourinho unhappy with Del Horno's personal lifestyle.

"Chelsea and Valencia have agreed a fee for the transfer of Asier Del Horno," Chelsea announced in a statement on the club's official website on Friday.

"The player has traveled to the Spanish club to negotiate personal terms."

A number of Spanish clubs were reportedly after Del Horno's signature, but the 25-year-old seems to be on his way to the Mestalla after Valencia agreed a deal with Chelsea.

Meanwhile, Chelsea have also agreed to a deal to sell winger Damien Duff to Newcastle United.

The Irish international agreed on the personal terms and is currently undergoing medical at St. James' Park.

Liverpool, Tottenham and Newcastle were all chasing Duff after the 26-year-old lost his first team place at Chelsea.