MADONNA is back in the recording studio hard at work on a new project, and this time she's teaming up with none other than "SexyBack" singer/songwriter JUSTIN TIMBERLAKE and super-producer TIMBALAND.

"Madonna has been in a recording studio in London with Justin Timberlake and Timbaland," her rep, LIZ ROSENBERG, tells ET.

This is the first time the pop diva has worked with either artist.

Meanwhile, the material mom is planning to return to Malawi, but denies reports that she is planning to adopt another baby.

"She is going to Malawi soon, but is not adopting another baby," Liz says. "It's a follow up visit as she's overseeing the building of a children's health care center as part of Raising Malawi's efforts in that country."