Get the latest news alerts: at Twitter.

The Associated Press

TRENTON, N.J. – Drugmaker (NYSE: MRK) on Thursday posted a bigger profit in the third quarter due to slightly higher sales and a huge gain from selling a business.

Merck is the process of expanding its production facility in Durham, N.C.

The maker of cholesterol drugs, vaccines and asthma and allergy treatment Singulair said net income was $3.42 billion, more than triple the $1.09 billion it made a year earlier.

That’s mostly due to Merck having to sell its half of the Merial animal health business so that regulators would approve its plan to buy New Jersey neighbor Schering-Plough Corp.

That sale brought in $2.8 billion, or $1.7 billion after taxes. Without it, profit would have been up roughly 58 percent from the 2008 third quarter.

Whitehouse Station, N.J.-based Merck is about to leapfrog from No. 8 to No. 2 in the pharmaceutical industry with its pending $41.1 billion acquisition of Schering-Plough. That will put it right behind Pfizer Inc., which last week bought Wyeth for $68 billion.

“We have made significant progress in our planning the past three months” for the merger, Chief Executive Richard Clark told analysts during a conference call. “We will be ready to hit the ground running on our first day of business as the new Merck.”

For the third quarter, Merck posted a 2 percent increase in revenue, to $6.05 billion.

It had earnings per share of $1.61, or 90 cents excluding the big gain from Merial. That beat analysts’ conservative expectations for earnings per share of 82 cents without items and revenue of $6 billion.