* Abbott adj. profit beats Street by 1 cent, rev in-line
* St. Jude CEO expects Abbott deal to close by year-end
* Abbott shares fall 2 pct premarket (Adds conference call details, background)
Oct 19 (Reuters) - Abbott Laboratories, which is acquiring St. Jude Medical Inc for $25 billion, reported a quarterly profit that edged past estimates as strength in its medical devices business more than offset a decline in its nutrition unit.
The company has been focusing on its device and diagnostics businesses this year. Apart from the St. Jude deal, Abbott is buying molecular diagnostic company Alere Inc for $5.80 billion.
The Abbott Park, Illinois-based company's stock was down about 2 percent in premarket trading on Wednesday.
St. Jude, which also reported its quarterly results, posted a quarterly adjusted profit of 99 cents, missing the average Wall Street estimate by 2 cents.
St. Jude is facing multiple challenges including an investigation by the U.S. Food and Drug Administration over claims that its heart devices are riddled with defects that make them vulnerable to fatal cyber hacks.
The company has sued short-seller Muddy Waters and cyber research firm MedSec Holdings after the two firms brought the alleged vulnerabilities to light.
St. Jude Chief Executive Michael Rousseau, on a post-earnings conference call, said he expected Muddy Waters to continue to "mislead" investors and patients about the cyber safety of its devices.
Last week, the company said it would recall some of its 400,000 implanted heart devices due to risk of premature battery depletion, a condition linked to two deaths in Europe.
Muddy Waters released several videos on Wednesday morning that claimed to be demonstrations of how attacks could be launched on St. Jude's implanted heart devices.
Reuters was unable to independently confirm claims in the videos, which were posted on a new website set up by Muddy Waters, www.profitsoverpatients.com. A St. Jude spokeswoman said the company had not verified the claims in the new videos.
St. Jude continues to expect the Abbott deal will be completed by the end of the year. The two companies on Tuesday announced a $1.12 billion deal to sell some of their devices to Japan-based Terumo Corp, an important step toward completing the acquisition.
Abbott's Alere deal is also in trouble with Alere suing the company, alleging that Abbott was dragging its feet on key antitrust submissions to sabotage the acquisition.
Abbott reported a net loss from continuing operations of $329 million, or 24 cents per share, primarily due to an adjustment of 66 cents per share associated with Abbott's equity investment in Mylan NV.
The company sold its generic drugs business catering to developed markets to Mylan in 2014.
Excluding items, Abbott earned 59 cents per share, on sales of $5.30 billion in the third quarter ended Sept. 30.
Analysts on average had expected earnings of 58 cents per share and revenue of $5.29 billion, according to Thomson Reuters I/B/E/S.
Reporting by Natalie Grover in Bengaluru and Ransdell Pierson in New York and Jim Finkle in Boston; Editing by Martina D'Couto