Boeing has today missed sharply-lowered Wall Street estimates for revenue and cashflow in the first quarter and suspended its 2019 outlook. 

The world's largest planemaker continues to suffer from the grounding of its 737 MAX jets. 

Boeing said it faced $1 billion in increased costs in the first-quarter ended March 31, related to the 737 aircraft as it halted deliveries of the grounded planes to customers around the globe. 

The company also said it was halting share buybacks. 

The fallout of a second deadly crash within months in March has seen Boeing cut production of the jets to 42 aircraft a month, down from 52.

Its operating cash flow in the first quarter was also around $350m lower than a year earlier. 

Boeing is also spending on developing a fix for an anti-stall software known by the acronym MCAS, which has been a common link in the separate chains of events leading to the two crashes within a span of five months. 

The company said it would be issuing a new forecast in the future when it has more clarity around the issues surrounding the 737 MAX. 

First-quarter operating cash flow declined to $2.79 billion, from $3.14 billion, missing the Wall Street's average estimate of $2.82 billion. 

Revenue fell 2% to $22.92 billion, below analysts' average estimate of $22.98 billion. 

Excluding certain items, Boeing said its core earnings fell to $3.16 per share, in the quarter from $3.64 per share, a year earlier. 

Analysts had expected Boeing to earn $3.16 per share.