Skymark Airlines Inc. may have filed for bankruptcy and seen its passenger numbers dwindle. It still holds an asset worth about $612 million in annual revenue that offers a path out of bankruptcy.

The budget airline has 36 takeoff and landing slots for local service from Haneda airport, or 8 percent of the rights there. One slot for domestic flights at the Tokyo airfield probably generates about ¥2 billion in sales annually, according to Hiroshi Hasegawa, an analyst at SMBC Nikko Securities Inc. in Tokyo.

Owning the third-most landing rights at Asia's second-busiest airport could help Skymark attract a partner to lift the company out of bankruptcy, where it landed last month with ¥71 billion of liabilities. Integral Corp., the private-equity fund that is helping the ailing carrier, has promised to hold on to all the Haneda slots and trim operating costs to turn the Tokyo-based airline profitable.