QVC Network Inc. and the Nasdaq stock market dismissed published reports that federal regulators were probing last Wednesday’s trading halt in QVC stock.A Nasdaq spokesman on Monday challenged a newspaper report that quoted unidentified sources as saying Securities & Exchange Commission chairman Arthur Levitt is looking into the matter. Trading in a particular issue — as a matter of policy — is halted for the dissemination of news into the marketplace. Last Wednesday, Nasdaq stopped trading in QVC stock for “news pending.” Since QVC did not release news of its merger deal with Paramount Communications to Nasdaq until after the close, its stock did not reopen that day. Trading in Paramount and QVC rival Viacom Intl. shares reopened shortly before the close on the New York and American Stock Exchanges, respectively. ‘Dirty politics’ Analysts and traders said the report’s sources were using “dirty politics” as a weapon in what has become a bitter and highly personal battle over Paramount. QVC shares showed little reaction to the story, closing down 50 cents at $ 39.50 . Nasdaq regulators had informed and satisfied the SEC about the halt last week , the spokesman said, rejecting the implication that the feds remain interested. QVC said the agency had made no “direct inquiries” on this. The SEC had no comment.