The American Postal Workers Union filed a formal report this week asking federal anti-trust regulators to strike down Staples' $6.3 billion deal to purchase Office Depot. APWU's report, entitled "No Sale: Why the Staples/Office Depot Merger Should be Blocked," asks the Federal Trade Commission to reject the acquisition like they did in the 90s on the grounds that the combined companies would undoubtedly raise prices for their products without similar retailers to keep them competitive — essentially…