Boeing struggles to convince investors that 737 Max is a safe investment

To restore faith in the 737 MAX, Boeing needs to prove its flagship jet is not just airworthy but also a safe investment.

At a gathering in Dublin this week of the titans of the multibillion-dollar aircraft leasing industry, which finances half the world's fleet, cracks were appearing in that effort. 

Boeing said on Tuesday its troubled workhorse —grounded last March after two crashes in which 346 people died — should receive approval by mid-year from US regulators, paving the way for hundreds of jets to resume service later this year. But in scores of high-stakes negotiations in the background, it is trying to convince banks, leasing firms and airlines that the investment case for thousands more of the jets remains intact.

Airplane owners and investors said some lenders were already demanding higher collateral in deals on the MAX. One airline said financing for pre-delivery payments had dried up amid the uncertainty — though the market won't be fully tested until closer to renewed deliveries.