(Reuters) - Boeing Co said on Monday it had entered into a $5.28 billion, two-year revolving credit agreement, as the U.S. planemaker contends with a prolonged slowdown in commercial air travel fueled by the COVID-19 pandemic. Earlier this month, Reuters reported that the company had approached a group of banks for a new $4 billion revolving credit facility and had the option to raise the size of to as much as $6 billion. (reut.rs/3rbbe5p) Citigroup, JPMorgan Chase Bank, BofA Securities and Wells Fargo Securities are the joint lead arrangers and joint book managers, the planemaker said here on Monday. The credit agreement is scheduled to end on March 19, 2023, Boeing said in a filing. Investment-grade rated companies use revolving credit facilities as backstop financing, with these facilities remaining undrawn for the most part.