Liverpool, English champions 18 times and winners of the European Cup five times, also said British Airways chief Martin Broughton had been appointed chairman with immediate effect and would oversee the sale.
"Following numerous expressions of interest from third parties, the Club has engaged Barclays Capital to advise on the sale process," the club said in a statement on their website.
"The Club has the full support of its existing bankers for this process and has financing in place which will fully support the Club's operations."
Hicks and Gillett said in a joint statement that being owners of Liverpool for the past three years had been a "rewarding and exciting" experience.
"Having grown the Club this far we have now decided together to look to sell the Club to owners committed to take the Club through its next level of growth and development," they said.
The American businessmen have faced intense scrutiny from Liverpool fans with protests for their removal a frequent occurrence at Anfield after ladening the club with the huge debts of its parent company.
SPORTING SUCCESS
The duo are facing a demand to repay 100 million pounds of the club's 237 million pounds debt to its lenders, Royal Bank of Scotland and U.S. bank Wachovia, in July.
Analysts had suggested Liverpool, who have plans for a new stadium at nearby Stanley Park, are worth 500 million pounds but Barclays is understood to believe it would fetch far more if given more time to improve its trading.
Broughton, also deputy president of the Confederation of British Industry, will work alongside Liverpool's exisiting management team in the day-to-day running of the club.
"I am excited and honoured to be taking up this position," the 63-year-old Briton said.
"Liverpool is one of the world's greatest clubs and my aim is to try and ensure that we find new owners who are able to build on the Club's recent improved financial performance in order to help deliver sporting success."
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