Stifel analysts pointed to operating cashflow being weaker year-on-year.

Companies are trading on about three or four times operating cashflow and generating reasonable returns on invested capital.

The company is still a formidable money machine -generating nearly $9 billion in operating cashflow in the second quarter.

Boeing is targeting operating cashflow of $15 billion and combined research & development and capital expenditure of $5.9 billion this year.

Its operating cashflow -a measure of profitability -rose by 6.9 per cent to €73.9 million for the same period.