FTC Challenges Cytyc’s Purchase of Digene

The Federal Trade Commission challenged Cytyc Corp.’s planned $283-million purchase of medical-test rival Digene Corp., saying the acquisition would threaten competition.

The commission authorized its staff to seek a court order to block the transaction. The purchase would allow Cytyc, the largest maker of kits for Pap tests, to consolidate its dominance of the market for cell-collection equipment used by medical-testing laboratories, the FTC said.

The FTC said it will seek to block the purchase until an administrative law judge considers the agency’s complaint.

Digene shares fell 31 cents to $12.69, while Cytyc shares fell 24 cents to $11.46, both on Nasdaq. The FTC announced its challenge after the close of regular trading.