The US Food and Drug Administration has delivered a warning notice to Boston Scientific, saying it uncovered ‘serious’ compliance problems at its manufacturing plants.

The news is a blow to Boston Scientific and comes at a terrible time - just as it has won a tug-of-war with Johnson & Johnson to acquire fellow medical device maker Guidant in a $27.2 billion deal. And the latter company is facing its own regulatory problems, having been forced to recall thousands of its pacemaker products last summer, and receiving a warning letter over regulatory compliance at a manufacturing facility last month.

Boston Scientific said it had received three warning letters from the FDA detailing compliance issues at three separate plants.

The latest is a company-wide notification – rarely sent out – and suggests that there are failings across Boston Scientific’s corporate structure with regard to its quality control structures and adverse event reporting, according to the agency, which said it would be taking regulatory action against the firm without further notice. The FDA also said that measures to put three other plants in order were inadequate.

In response Boston Scientific stressed that the notice does not imply any product performance issues, such as caused the Guidant pacemaker recall, and does not prevent it from distributing any of its products, including its Taxus (paclitaxel) drug-eluting stent.

“We have clearly not done enough to resolve the issues raised by the FDA last year,” said Jim Tobin, Boston Scientific’s chief executive. “We are confident we have addressed many of these issues, but others have not yet been fully resolved,” he noted, adding that he expects to resolve the outstanding problems ‘promptly’.

The company said it intends to meet with the FDA next week to discuss the issues raised by the agency.