Metropolitan Expressway Public Corp. said Monday it may hike expressway tolls in the Tokyo area by about 100 yen to 800 yen as early as December.

The public corporation plans to ask its advisory panel on highway fares to begin studying the hike in September, officials said.

Once the panel approves the move, the corporation will seek the consent of the five prefectures and cities that have invested in the body, including the Tokyo Metropolitan Government.

It will then seek the approval of the Land, Infrastructure and Transport Ministry.

Along with the toll hike, it also plans to ask the panel to study the introduction of a discount for users of the Electronic Toll Collection system.

The discount may be similar to a current one offered to people who purchased coupons. It is also considering holiday and nighttime discounts.

If the discount system expands or a sharp decline in users is anticipated, the fare hike may be even bigger than 100 yen, the officials said.

A government panel is currently discussing the privatization of the public corporation along with three others -- Japan Highway Public Corp., Hanshin Expressway Corp. and Honshu-Shikoku Bridge Authority.

However, whether the fare hike will be approved by the land ministry will probably depend on political decisions following the ongoing privatization discussions and the country's economic situation.