WASHINGTON - Fleishman-Hillard's purchase of lobbying shop Quinn Gillespie, one of the most anticipated acquisitions of 2002, fell apart this week when the two sides were unable to reach a final agreement.In September, the two firms reached an "agreement in principle" for QG to be acquired by the Omnicom-owned agency. But several months of negotiations, characterized by both sides as sluggish and frustrating, failed to produce terms acceptable to either side. According to a top executive at QG, the terms of the deal changed "at literally the last minute." Founded just three years ago, QG quickly became one of the most sought-after lobbying shops in Washington due to its bipartisan credentials and its close ties to the Bush White House. The firm was founded by former Clinton White House counsel Jack Quinn and veteran GOP strategist Ed Gillespie, who was rumored earlier this year to be considering a job in the Bush administration - a factor that the QG executive denied played a role in the breakdown.