INDIANAPOLIS (AP) – In another blow to troubled Guidant Corp., the Food and Drug Administration has warned the medical device maker that it has failed to resolve all of the problems the agency found earlier this year during an inspection at the company’s cardiac unit in St. Paul, Minn.

The Indianapolis-based company said Tuesday it received the FDA’s warning letter Dec. 23, about three months after it replied to a report by the agency on manufacturing and record-keeping problems it found during an August inspection of its St. Paul operations.

Guidant’s announcement of the letter came four days after the company said it would adjust fourth-quarter revenue estimates to well below Wall Street expectations as it tries to regain consumer confidence after months of product recalls and safety warnings. It also comes as Natick, Mass.-based Boston Scientific Corp. duels with Johnson & Johnson to pay more than $20 billion for the company

The FDA’s letter states that it will not approve for sale certain Guidant devices made at its St. Paul operations until the problems are corrected.

Jan Wald, an analyst with A.G. Edwards & Sons, said the FDA’s warning letter had been anticipated by the investment community in the wake of Guidant’s announcement on Sept. 22 that the FDA had found “15 observations,” or problems, at its Minnesota manufacturing operations.

“If the company can resolve the issues quickly it shouldn’t be a problem, but if it goes longer than six to nine months, it could pose a problem,” Wald said.

The FDA’s four-page letter states that the “significant violations” of the federal government’s good manufacturing practice requirements found at the St. Paul facility “may be symptomatic of serious underlying problems in your firm’s manufacturing and quality assurance systems.”

Guidant said in a statement that it will respond promptly to the FDA’s letter, and “has taken a broad, thorough and systemic review of its quality system and has made substantial steps toward addressing all of the” problems found by the agency.

The company said it has completed 90 percent of the commitments it made to the FDA in its initial response to the agency’s concerns. It also said it was on schedule to complete its remaining commitments and is giving the FDA monthly progress updates.

Guidant spokesman Steven Tragash said the company had no comment beyond Tuesday’s news release and referred calls to the FDA.

FDA spokesman Jason Brodsky said Guidant has 15 days from the date of the warning letter, sent Dec. 22, to update the agency on the corrective actions it has taken to “address the deviations we noted in our warning letter.”

“The company has already taken some steps to address the problems cited during our inspection,” he said, adding that Guidant still has not resolved all the matters.

The FDA issues warning letters for many reasons, including if it disagrees with a company’s response to problems found during an inspection, or if the company fails to resolve a problem.

Since June, Guidant has recalled or issued warnings about 88,000 heart defibrillators and almost 200,000 pacemakers because of reported malfunctions. The company is under investigation by federal and state officials and faces dozens of lawsuits over its recalls.

While Guidant said in its statement Tuesday it “believes that it can fully address the concerns of the FDA without a material impact to its business,” such an impact could affect its pending acquisition. Johnson & Johnson lowered its bid to $21.5 billion from $25.4 billion in the wake of the recalls that began after a December 2004 takeover deal was announced.

Boston Scientific last month offered $25 billion, or about $72 per share, for Guidant. A spokesman for Boston Scientific, Paul Donovan, said Tuesday the company continues “to move forward on our due diligence with the goal of reaching a definitive agreement with Guidant.”

Guidant shareholders are scheduled to vote next month on the revised merger deal the company reached with Johnson & Johnson on Nov. 14. The special shareholder meeting, set for Jan. 27, is to be held at Guidant’s corporate headquarters in Indianapolis.

Jeff Leebaw, a spokesman for New Brunswick, N.J.,-based Johnson & Johnson, said Tuesday the company would not comment on the warning letter.

Stanford Group Co. analyst John Putnam said the FDA warning letter will only add to Guidant’s image problems – and the work to overcome them that either Boston Scientific or J&J will inherit, depending on which company acquires Guidant.

“Clearly, this is not a situation that’s going to turn around on a dime. Whoever gets it is going to end up with a bunch of problems they’re going to have to work on and solve,” he said.

Guidant is among three U.S. companies that dominate the global market for implantable heart defibrillators and pacemakers: industry leader Medtronic Inc. of Fridley, Minn.; Guidant; and St. Jude Medical Inc. of Little Canada, Minn.

Shares of Guidant closed down $2.29, or 3.4 percent, to $64.69 in trading Tuesday on the New York Stock Exchange. Boston Scientific shares fell 67 cents, or 2.6 percent, to close at $25.17 on NYSE, and shares of Johnson & Johnson dropped 81 cents, or 1.3 percent, to $60.30.

AP-ES-12-27-05 1832EST