By Amrutha Penumudi

(Reuters) - Abbott Laboratories reported better-than-expected quarterly sales and profit as strong sales in its medical device business more than made up for the hit from an economic turmoil in Venezuela.

Abbott is one of the major U.S. companies to be affected by troubled operations in Venezuela.

The Latin American nation's economy contracted by 4.5 percent in the first nine months of last year as plunging oil prices, and what critics of President Nicolas Maduro see as policy missteps, took an increasing toll.

Venezuela's official annual inflation rate was the world's highest at 141.5 percent in the nine months.

Abbott, which rakes in two-thirds of its revenue from outside the United States, said emerging market sales increased 1.1 percent but would have risen 4.8 percent excluding the impact of Venezuelan operations.

The company's results, however, beat Wall Street estimates, largely helped by its booming medical device business, where sales rose 6.4 percent to $1.37 billion in the second quarter.

Abbott's device unit develops products for heart, diabetes and eye patients and has been helped by launches including glucose monitor FreeStyle Libre and MitraClip, which repairs heart valves less invasively.

Abbott is in the process of acquiring St. Jude Medical Inc for $25 billion. St. Jude on Wednesday reported second-quarter earnings and revenue roughly in line with Wall Street estimates.

Miles White, chief executive of Abbott, said he had still expected to close the transaction before year-end, as the company prepares to respond to a second request of information from the U.S. Federal Trade Commision.

Abbott's acquisition of diagnostic company Alere Inc however, continues to see challenges, especially after Alere was subpoenaed by the U.S. Department of Justice over its sales practices.

Alere rejected a request by Abbott to terminate the deal for a breakup fee in April.

"To be honest, no matter what kind of teeth grinding and gnashing we go through with them .. one thing I'm certain of is that they are trying to do everything they can, in their way to address the challenges," Miles said on a conference call with analysts.

On an adjusted basis, Abbott earned 55 cents per share in the quarter ended June 30, above the average analyst estimate of 53 cents, according to Thomson Reuters I/B/E/S.

The company's net sales rose 3.2 percent to $5.33 billion, beating analysts' estimate of $5.24 billion. (http://prn.to/2atEUVO)

Abbott's shares were up 2.3 percent at $42.76 in mid-morning trading.

(Reporting by Amrutha Penumudi in Bengaluru; Editing by Maju Samuel)