FRANKFURT, Germany (AP) _ Germany's antitrust watchdog is investigating Deutsche Telekom on suspicion it has charged competitors unfair fees for accessing its directory data.

Deutsche Telekom, the former telephone monopoly that is now partly privatized, charges a fixed rate for its directory data. The Federal Cartel Office wants it to adjust the rate based on usage or market share.

A spokesman for the Berlin-based cartel office said Wednesday the fixed pricing hindered new operators from joining the market because of the initial high costs.

He said the investigation started in the middle of the year, and that Deutsche Telekom said it would respond to the allegations in writing on Dec. 15. He gave no timetable for a final ruling in the case.

Deutsche Telekom declined to provide further details of current talks with the cartel office.

Telekom lost its monopoly Jan. 1 with the liberalization of Germany's telecommunications market in keeping with European Union standards. But it still has a virtual monopoly on customer profile data, the cartel spokesman explained.

According to the cartel office, Deutsche Telekom charges competitors up to 170 million marks, or $100 million, if they want to offer the same full-range directory assistance Telekom does. For that fee, a competitor could use Telekom data to provide directory assistance, telephone books and CD-roms.