Boeing Co has approached a group of banks for a new $4 billion revolving credit facility, a person familiar with the matter said, reports Reuters. Boeing battles a prolonged slowdown in commercial air travel due to the COVID-19 pandemic.

Investment-grade rated companies use revolving credit facilities as backstop financing, with these facilities remaining undrawn for the most part.

The U.S. jet manufacturer has the option to raise the size of the two-year credit facility to as much as $6 billion, the person said on Thursday.

A Boeing spokesman declined to comment. The development was earlier reported by Bloomberg News.

Boeing Chief Financial Officer Greg Smith had discussed raising more debt at the company's quarterly earnings call in January.

Smith said Boeing has "sufficient liquidity" currently, but it continues to consider all options to strengthen its balance sheet.