Spirit AeroSystems said on Tuesday it would receive up to $350 million in advance payments from its largest customer Boeing and up to $107 million from Airbus , giving the struggling supplier a lifeline as it burns cash after four consecutive years of losses.

Boeing has agreed to pay Spirit AeroSystems up to $350 million in advance to keep producing products for it as the fuselage supplier works through a liquidity crunch. The jet maker said Tuesday that the advance payments are intended to help Spirit address high levels of inventory and lower operational cash flows.

Boeing Co. will advance Spirit Aerosystems Holdings Inc. as much as $350 million as the planemaker gives its most important supplier a financial lifeline ahead of the planned purchase of the company.