MOSCOW, October 15 (RIA Novosti) - Russia's Federal Air Navigation Authority is to suspend services to all flights by nine regional air companies from October 17 over unpaid fees, the air traffic regulator said Wednesday.

The debts owned by the air companies, which include airlines, aircraft-building companies and an air school, range from 19 million rubles ($738,000) to 1,404 rubles ($54).

"In line with legislation, the following consecutive sanctions are to be imposed on air carriers in arrears for air navigation services: warning, restricting services to charter flights and suspending services for all flights," the regulator said in a news release, adding that the companies had repeatedly been requested to pay their debts.

The list of the penalized companies includes Dalavia, a state-owned carrier that suspended ticket sales in September after its bank accounts were frozen over a debt of more than 240 million rubles ($9.5 million).

Another airline, Omskavia, was part of the AiRUnion alliance that was hit by a cash crisis leading to flight delays across Russia in August. The alliance broke up after the government decided to transfer its stakes in AiRUnion to the state-run Russian Technology Corporation and use them to form a new carrier.

Moscow-based Interavia has come under the focus of the Federal Air Transport Agency over repeated flight delays at Moscow's Domodedovo Airport. Media said the delays were caused by the airline's debt to fuel companies. The regulator has launched an inspection, saying the independent airline could have its license revoked.