Colony Capital LLC, a Santa Monica investment firm known for its real estate dealings, has entered into a long-term agreement with Annie Leibovitz to help the celebrity photographer manage her debt and stay out of bankruptcy.

Under the agreement first reported Tuesday by the Financial Times, Colony will partner with Leibovitz to market her portfolio – including future traveling exhibitions or books of her iconic work.

Representatives of Colony did not respond to requests for comment.

The 60-year-old photographer, known best for her celebrity portraits in magazines such as Rolling Stone and Vanity Fair, has had well-publicized financial troubles for more than a year, falling behind on a loan with Art Capital Group, a Manhattan firm that provides financing for artists.

Her problems stem from late 2008, when Leibovitz borrowed $15 million against collateral of her homes and the rights to her portfolio. Leibovitz missed a deadline last summer to repay Art Capital, which filed a lawsuit against the photographer in July. The firm later withdrew the lawsuit and extended the due date on payment.

Under the latest arrangement, Art Capital has been paid and Leibovitz will retain control of the photographs.

Colony, headed by Southern California financier Tom Barrack, has invested more than $39 billion primarily in real estate-related assets since its founding in 1991. Recently, Colony acquired the $23.5 million loan on Michael Jackson’s Neverland Ranch.