Shares of T-Mobile (TMUS) and Sprint (S) are under pressure on Wednesday after a Wall Street Journal report suggested their merger is unlikely to be approved by the Department of Justice as currently structured. Sprint chairman Marcelo Claure has since said the article is "not accurate," while T-Mobile CEO John Legere said via Twitter that the premise of the story is "simply untrue."

MERGER UNLIKELY TO BE APPROVED BY DOJ: According to a report by The Wall Street Journal's Drew FitzGerald and Brent Kendall on Tuesday, the U.S. Department of Justice staffers have informed T-Mobile and Sprint that their planned tie-up is unlikely to received approval as currently structured. The carriers are facing challenges on several fronts, but their biggest obstacle comes from the DOJ's antitrust unit, which is weighing whether the deal would present an unacceptable threat to competition, FitzGerald and Kendall said. In a meeting earlier this month, DOJ staffers laid out concerns with the proposed merger and questioned the carriers' arguments that the tie-up would create important efficiencies for the merged entity, the authors added.

STORY 'SIMPLY UNTRUE': Meanwhile, T-Mobile CEO John Legere said via Twitter that the premise of the Wall Street Journal story saying that the company's proposed merger with Sprint is facing resistance from Justice Department staff is "simply untrue." "The premise of this story, as summarized in the first paragraph, is simply untrue," he tweeted. "Out of respect for the process, we have no further comment. This continues to be our policy since we announced our merger last year." Marcelo Claure, the chairman of Sprint, also said the Wall Street Journal article is "not accurate." In a tweet, he added that, "We continue to have discussions with regulators about our proposed merger with @TMobile. That process is ongoing and we have no further comment."

60% APPROVAL PROBABILITY: In a research note to investors, Wells Fargo analyst Jennifer Fritzsche pointed out that the Wall Street Journal reported DoJ staff expressed concerns about the Sprint/T-Mobile merger at a meeting earlier this month as it would present a ''threat to competition." However, the analyst noted that she maintains her 60% odds that the deal gets approved, and does not see this report as “new news.” While Sprint's road is much more unknown in the event of no merger, in either scenario Fritzsche continues to favor T-Mobile's shares.

PRICE ACTION: In late morning trading, shares of Sprint have dropped almost 6% to $5.68, while T-Mobile’s stock has slipped about 4% to $71.46.