Arthur Carter, the Wall Streeter turned boutique press baron, may have finally found a buyer for his city weekly, the Observer: the founding trio of the Tribeca Film Festival, Robert De Niro, producer Jane Rosenthal (Meet the Fockers), and her venture-capitalist husband, Craig Hatkoff. “Nothing is signed on paper, but they’re definitely looking at it, and definitely looking at it very seriously,” says one insider. Says another, “They’re kicking the tires.” The Observer is estimated to bleed $2 million a year, enough to scare off many potential buyers since Carter got serious about selling it early this year. But the speculation is that DeNiro & Co. are hoping for advertising synergy with the Film Fest sponsors (AmEx, Pepsi, Sony, Nokia, L’Oréal). Meanwhile, a Tribeca Productions–owned Observer could support Tribeca Productions projects à la Talk and Miramax. A Tribeca spokesman declined to comment; Neither Carter nor editor Peter Kaplan returned calls.