range of $500 million to $1 billion. Companies usually try to reduce the debt level and reorganize business operations through the Chapter 11 bankruptcy route. Solyndra is the third U.S. solar company to seek bankruptcy protection in the recent past. Former Wall Street high flyer Evergreen Solar Inc filed for Chapter 11 two weeks ago, followed four days later by SpectraWatt Inc, a private company that was backed by Intel Corp. In a statement last week, Solyndra said it could not compete with bigger overseas rivals. Earlier this year, cuts to generous solar subsidies in No. 2 market Italy stalled development of solar projects and led to a global glut of solar panels that sparked a 25 percent drop in prices. Even industry heavyweights such as China's Suntecld have the ability to use its control over backhaul, roaming and spectrum, and its increased market position to exclude competitors, Sprint said in a statement. "With today's legal action, we ... expect to contribute our expertise and resources in proving that the proposed transaction is illegal," Sprint's vice president of litigation Susan Haller said. The lawsuit was filed in federal court in the District of Columbia. Last week, a similar lawsuit was brought on by the U.S. government. Justice Department officials had warned that allowing AT&T to gobble up the No. 4 carrier would be disastrous for consumers.  evron as saying Wednesday. A Chevron spokesman announced the impending agreement at a meeting between Vietnam's National Committee for Financial Supervision and the US-ASEAN Business Council in Hanoi Tuesday, news website Vneconomy reported. The companies will build a 400-kilometer gas pipeline and three gas-fired power plants, scheduled to start operating in 2015, the report said, without giving further details. PetroVietnam will likely invest $3 billion in the pro