* Up to 23 737 MAX deliveries delayed due to grounding
* A320neos delayed due primarily due to industrial constraints
* BOC working with Boeing on revised delivery timeframe (Adds Boeing, Southwest timelines for return to service)
SINGAPORE, July 30 (Reuters) - Aircraft lessor BOC Aviation Ltd said on Tuesday it expected up to 30 Boeing Co and Airbus SE jets that had been scheduled to arrive this year could be delayed, primarily due to the Boeing 737 MAX grounding.
BOC said 18 jets that had been due in the first half had been delayed, including 12 A320neos due primarily to industrial constraints and 6 737 MAXs as a result of the grounding.
For the full year, up to 7 A320neos and 23 737 MAXs could be delayed, including three for which an airline customer has the right to acquire upon delivery, Asia's second-biggest aircraft lessor said in a statement.
BOC said it was working with Boeing on a revised delivery timeframe.
Boeing last week estimated a return to service for the jet would begin early in the fourth quarter, but it did not rule out further reducing or temporarily shutting down production of the plane if that forecast needed to be revised.
U.S. carrier Southwest Airlines Co last week removed the 737 MAX from its schedules until Jan. 5, 2020, saying it would need one to two months following regulatory approval to train pilots and prepare the jets for fresh commercial service. (Reporting by Jamie Freed; Editing by Stephen Coates)