Spears' manager Larry Rudolph said in a statement that the pop singer was released on Tuesday by the Promises Malibu Treatment Center "after successfully completing their program."

"We ask that the media respects her privacy as well as those of her family and friends at this time," the statement said.

Spears, 25, checked into Promises on February 21 after shaving her own head following weeks of erratic public behavior that coincided with an escalating divorce battle.

The specific treatment Spears was seeking was not made clear but the former teen idol was photographed on several occasions making her way to Alcoholics Anonymous meetings outside the facility during her stay there.

Some celebrity watchers speculated that she may have been battling post natal depression after the birth in September 2006 of her second baby in 12 months.

The minimum stay for most centers is 30 days but Promises founder Richard Rogg has said the usual stay at his facility is about 45 days. Country star Keith Urban recently spent three months at the Betty Ford Center for alcohol abuse.

Promises, a celebrity magnet nestled in the mountains overlooking the Pacific Ocean, offers a tough-love philosophy that requires patients to perform menial chores in a highly pampered setting.

In the week leading up to her arrival at Promises, Spears had spent less than a day at guitarist Eric Clapton's Crossroads rehab center in Antigua.

She then returned to Los Angeles, where she tearfully shaved her head in a beauty salon, and then checked in and swiftly out of Promises before deciding to stay there.

Spears filed for divorce from second husband Kevin Federline in November after two years of marriage and two children. She was photographed without panties while hitting the nightclub circuit.

Celebrity Web site TMZ.com reported that Federline and Spears have now agreed to share custody of their sons while they finalize their divorce. Other celebrity Web sites said Federline and the boys had visited Spears several times while she was at Promises.

Her recording career, meanwhile, is dormant. The singer who shot to fame as a teenager in 1999 and has sold an estimated 70 million records, released her last album of new material, "In the Zone," in 2003.