AWG said six poorly performing contracts had lost another £10m in the year to 31 March, and that closing Morrison's international division would cost £5m. The group refused to rule out taking legal action against brothers Gordon and Sir Fraser Morrison, who sold their family business to AWG for £262.5m in August 2000.
AWG last year posted operating losses of £33.8m for Morrison Construction, and was forced to cut £22.9m off its estimate of the value of the business.
A spokesperson said the £80m Broadway Plaza mixed-use development in central Birmingham was the final UK contract to be resolved. It is about a year late, and is now due to be completed in the autumn.
Morrison's development arm was also the project's developer. The other five UK contracts were "essentially complete", according to the spokesperson.
The business is now much more focused on what work it is taking on
AWG said the construction losses had been capped at £15m for the year to 31 March, and were unlikely to recur in future years because AWG had changed the management style at Morrison.
"In the past, the construction division was actively encouraged, if that's a strong enough word, to build projects that the development division was involved in," said the spokesperson. "This is no longer the case, and the business is much more focused on what work it is taking on."
AWG said it was closing Morrison's international businesses in Ghana and Azerbaijan, a move that will cost £5m. The group said they had not been profitable.
The spokesperson said AWG had nearly completed its investigation into the Morrison contracts that it started last June. Once that was completed, AWG would decide whether to sue the Morrison brothers. The spokesperson said: "It is a live issue; we expect to make a decision this summer".