U.S. philanthropic foundations have pledged more than $330 million to help preserve the Detroit Institute of Art's collection and assist in shoring up the cash-strapped city's employee pensions, the mediators overseeing Detroit's bankruptcy negotiations said on Monday. _0"> In a statement, the mediators said other foundations are expected to pledge assistance in the near term. "As the mediators attempt to achieve a settlement of all claims, it bears emphasis that the foundations' agreement to participate is specifically conditioned upon all of their funds being committed to the twin goals of helping the city's recovery from bankruptcy by assisting the funding of the retirees' pensions and preserving the DIA's art collection as part of an overall balanced settlement of disputes in the bankruptcy," the mediators said. Last month, auction house Christie's appraised the value of Detroit-owned works at the institute at $454 million to $