UPDATE 1-U.S. FDA says more action needed on Philips AEDs

(Adds company comments, paragraphs 7-8)

WASHINGTON, Feb 27 (Reuters) - The U.S. Food and Drug Administration issued a warning letter to Philips Medical Systems about problems with the company's portable devices that shock a patient and restore a normal heart beat, according to a copy made public on Tuesday.

The FDA letter, dated Jan. 29, said the unit of Philips Electronics (PHG.AS) needed to take additional corrective steps to address intermittent switch failures reported by users in FR2 and FR2+ models of automatic external defibrillators.

Although the company determined the failures were due to a manufacturing problem involving wash water contamination and recalled units from affected lots, the FDA said Philips must make changes to operating procedures that allowed the problem to occur.

Complaints about the "on/off" or "shock" buttons not working on the company's HS1 units also need to be addressed further, the FDA letter said.

"You do not explain how retraining employees on the existing assembly procedures is expected to correct this problem, given that these same procedures were in place when the faulty units were manufactured," the agency said.

The FDA told Philips to notify it within 15 working days of additional steps it would take to correct the violations.

Steve Kelly, a spokesman for Philips Medical Systems, said the company was working with the FDA on the issues raised in the letter. The firm submitted a response to the letter on Feb. 22, he said.

"We are doing our best to comply with the concerns they have," Kelly said.