KUALA LUMPUR (Reuters) - Malaysia"s AirAsia X Bhd AIRX.KL plans to revise its $15.3 billion debt restructuring plan to address concerns raised by a creditor as its cash is running out fast, people with direct knowledge of the matter said. The budget carrier is seeking to reconstitute the $15.3 billion of unsecured debt into a principal amount of 200 million ringgit ($48 million) and have the rest waived. But creditor Malaysia Airports Holdings Bhd (MAHB) MAHB.KL filed a lawsuit last week to claim 78 million ringgit owed by AirAsia X and a separate application to be excluded from the restructuring scheme, arguing that its debts were secured. A source, who was not authorised to speak publicly about the plans, told Reuters the legal action against the airline could delay its debt restructuring plan and bid to stave off liquidation. The source said AirAsia X, the long-haul arm of AirAsia Group Bhd AIRA.KL, has less than six months of cash left and has been looking to convene a meeting of creditors to vote on the scheme. "It needs to move on and have that meeting as soon as possible," the person said. “Fundraising is expected to take a couple of months at least so it’s imperative for the company to complete restructuring by January or February.” AirAsia X declined to comment. Airport operator MAHB said on Sunday its attempt to recover debt from AirAsia X would not derail the airline’s scheme. But the legal suit follows similar action taken by another creditor. Aircraft lessor BOC Aviation Ltd 2588.HK filed a lawsuit against AirAsia X and its subsidiary in August to claim $23 million in debt and this month applied to intervene in the airline"s court application for its scheme. The airline"s restructuring proposal needs approval from creditors holding at least 75% of the total value of the debt, and the source said that the bulk of the figure is linked to future aircraft orders and it gives Airbus SE AIR.PA nearly 75% on its own. “No creditor will want to make a decision if they don’t know what the outcome with MAHB is,” another source said, adding that MAHB could have the financial stamina for a legal battle but AirAsia X did not. Post restructuring, the airline plans to raise up to 500 million ringgit to restart the company, it said on Monday. Shares in AirAsia X have hit all-time lows in the last three weeks. ($1 = 4.1630 ringgit)