Highly-leveraged U.S. energy companies are struggling to carry out debt swaps as part of their survival strategy because plummeting oil and gas prices make investors either avoid such deals or demand tougher terms. Last year, at least 10 exploration and production companies, including California Resources Corp ( CRC.N ), managed to ease financial pressure by persuading investors to accept some losses on their bond holdings in return for new debt that often matures later and offers better collateral. Yet since prices tumbled further early this year, investors have grown more worried that some firms may not survive the rout. They see no point in accepting debt with potentially better collateral if it could mean nothing once the firm hits the wall. The […]