In April, Boeing provided a $425 million advance to support Spirit's liquidity. Spirit, Wichita's largest employer with around 12,800 full-time workers, previously disclosed it has spent all of that money, as well as the entirety of a $350 million bridge loan that was set up earlier this year.

Spirit Aerosystems (NYSE:SPR) rose 1.6% after the company confirmed that it entered into an advance payments pact with Boeing (BA). Boeing (BA) committed to pay as much as $350 million in the advanced payment pact,

The payments are intended to help address high levels of inventory and lower operational cash flows.

Spirit AeroSystems (NYSE: SPR) today announces an Advance Payments Agreement with Boeing, in which Boeing has committed to pay Spirit, as advance payments, up to a total of $350,000,000.00 to produce Boeing products at the rates required by Boeing.

The airframe manufacturer will get a new cash infusion from its major customer to ensure it can remain financially stable and maintain inventory, reduce operating expenses,

Spirit AeroSystems and Boeing are close to reaching a funding agreement that would give a cash lifeline to the struggling Boeing supplier, an industry source familiar with the matter said.

One week after Spirit AeroSystems announced it has "substantial doubt" about its ability to continue as a going concern, Boeing is offering help.

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.