UPDATE 1-States allege Abbott blocked generic TriCor

(Adds details on generics, new Abbott formulations)

NEW YORK, March 18 (Reuters) - State regulators are suing Abbott Laboratories Inc (ABT.N) and Solvay (SOLB.BR) unit Fournier, alleging the drug makers illegally conspired to prevent and delay low-cost generic versions of their TriCor cholesterol drug.

The suit was filed on Tuesday by attorneys general of 18 states and the District of Columbia in U.S. District Court in Delaware, the Iowa attorney general's office said.

The lawsuit alleges that Abbott and Fournier brought sham patent-infringement lawsuits against generic companies, without a reasonable basis to believe the patents were enforceable, according to a copy of the lawsuit posted on the Iowa attorney general's Web site.

According to the lawsuit, Abbott and Fournier also improperly attempted to monopolize the TriCor market by reformulating it to different dosage strengths and ending sales of the original formulations.

The drug, which is a leading treatment for a type of blood fat called triglycerides, has annual sales of more than $1 billion.

Abbott spokeswoman Melissa Brotz defended Abbott's actions as lawful.

"There is nothing anti-competitive about ceasing manufacturing and marketing (of) older versions of products when improvements are developed," Brotz said.

Brotz said the improvements of the new formulations include having to take fewer pills, requiring lower dosages and being able to take them with or without food.

She said eight generic forms of TriCor are now on the market, and were launched beginning in 2002, soon after Abbott stopped selling its original 67 milligram form of TriCor and instead began selling new 54-milligram and 160-milligram formulations.

"Once we began selling improved formulations, there was no need to keep selling the old formulation," Brotz said.

She said the discontinued formulation had been approved for patients with high triglycerides at risk of pancreatitis, a potentially dangerous inflammation of the pancreas. The new formulations, however, were also approved to raise levels of heart-protective "good" HDL cholesterol, she said.

Abbott in 2004 launched 48-milligram and 145-milligram forms of TriCor, which are patent-protected for another decade, Brotz said. (Reporting by Lewis Krauskopf and Ransdell Pierson; Editing by Maureen Bavdek and Carol Bishopric)