(Reuters) - AbbVie , a pharmaceutical company has sought an injunction to block Europe's medicines regulator from releasing "confidential" and "commercially-sensitive" information on its blockbuster rheumatoid arthritis drug, a spokeswoman for the U.S. drugmaker confirmed on Sunday.

The Financial Times reported earlier on Sunday that the Chicago-based company, which was spun off from Abbott Laboratories , had taken legal action against the European Medicines Agency to stop it from releasing data on the effects in individual patients in clinical trials for its drug Humira.

The European Medicines Agency could not be reached for comment.

Sales of the drug, by far the company's biggest product, jumped 17 percent last year to $9.27 billion.

The European Medicines Agency, criticized in the past for excessive secrecy, is opening its data vaults to systematic scrutiny, a move that will let independent researchers trawl through millions of pages of clinical trial information.

It is blow for the pharmaceutical industry, which guards its commercial secrets fiercely and has not before been required to share its data with outside researchers.

(Reporting by Karen Rebelo in Bangalore; Editing by Diane Craft)