LONDON (AP) _ Top ticket prices at the Royal Opera House will exceed $170 for the first time next season, the financially struggling company says.

Beginning in September, opera tickets at the theater in Covent Garden will jump on average by 17 percent while ballet seats will rise 25 percent, the company announced Monday.

The decision to raise prices comes as the theater struggles with an accumulated deficit of about $8.5 million. The company projects a deficit of $3.4 million this season.

''Even in a perfect world our ticket prices would have to rise to keep pace with inflation,'' said Jeremy Isaacs, general director of the Royal Opera House. ''We have taken these steps with reluctance in order to sustain rather than reduce our service to our audiences.''

Prices for 12 of the 126 upcoming opera performances will range from $5 for seats in the upper balcony, to $172 for the house's best seats. The most expensive ticket last season was $153.

For 12 performances, including Joan Sutherland's farewell appearance in ''Die Fledermaus'' and operas starring Jose Carreras and Placido Domingo, ticket prices will range from $10 to $190.

Ballet tickets will cost from $2.55 to $83.

''Even at these prices, subscription sales are as high as ever,'' said opera spokesman Ewen Balfour.