[ by Melanie Gretchen ] A former vice chairman of Dewey & LeBoeuf told the law firm that it owes him $61 million, upon resigning of Friday in the latest blow to the dying behemoth.  Morton A. Pierce departed to White & Case for another firm with seven of his partners, according to a person with direct knowledge of the matter who requested anonymity because he was not authorized to speak publicly about it. Status Report. As of last week, more than a third of its 300 partners had left, the copy center and mail room had begun winding down, and partners were told that they could lose their jobs.  This week, Dewey told secretaries that Friday would be their last day, though remaining partners and associates have not been given such notice. Mr. Pierce, 63, was one of the highest-paid partners at Dewey, with a package paying him $6 million a year for 6 years.  His history at the firm runs deep: he was the chairman of the legacy firm Dewey Ballantine, which in 2007 merged with LeBoeuf, Lamb, Greene & MacRae to form Dewey & LeBoeuf.  Like other partners who have lost money, his claims of $61 million may relate to a combination of money invested in the firm, deferred compensation and retirement funds, legal industry experts say. For further details, go to [Dealbook, 5/7/12].