Earnings at ST Engineering fell in the third quarter, dragged down mainly by its aerospace and land systems businesses.

Net profit declined 10 per cent over the same quarter year to $131.4 million, while revenue was up 1 per cent to $1.55 billion.

Sales in the aerospace and electronics sectors were comparable with a year ago, while turnover in the land systems sector dropped 11 per cent to $348 million.

Revenue for the marine sector surged 25 per cent to $296 million.

Commercial sales contributed 63 per cent, or $1 billion, of the group's revenue this quarter.

The company expects to recognise about $1.5 billion out of its $12.5 billion order book in the remaining months of 2013.

In the third quarter, the aerospace and electronics sectors announced contracts worth over $1 billion.

The defence contractor and aircraft maintenance firm ended the quarter with $2.1 billion cash and cash equivalents including funds under management.