The Six Flags Corp., which spent more than $30 million to turn an old Baltimore power plant into an entertainment and amusement center, will invest more than $1 million in modifications to try to boost sagging attendance, said company officials.

Mayor William Donald Schaefer, who expressed disappointment with some of the attractions, said he is pleased by the proposed improvements at the gigantic amusement-entertainment center known as the Power Plant.

The city, for its part, will plant trees and add lighting around the Power Plant as part of an effort to jazz up the center's appearance.

Six Flags will be getting rid of some attractions and adding others, said Richard Knight, vice president of finance and special attractions for the Chicago-based amusement company. It will give the huge building a flashier facade and add a cabaret-type bar and restaurant with live entertainment.

The Power Plant got off to a slow start in July, averaging 2,000 to 2,500 visitors on weekdays and 4,000 to 5,000 on weekends, company officials said. General manager Raymond Grable said attendance has fallen recently.

Admission prices currently are $7.95 for adults and $5.95 for children ages 4 to 11, but they are expected to change shortly.