MOWLEM'S environmental business is the latest part of the company to be put up for sale.
The news comes as Carillion was due to complete formally its £313 million takeover of the company yesterday (Wednesday) with Mowlem's 26,000 staff officially becoming Carillion employees today.
An information pack on the Environmental Sciences Group has been drawn up. The planned disposal has been given the codename 'Project Mint'.
The division employs 900 staff across 16 offices in the UK and Ireland and carries out work in a number of fields including soil mechanics and contaminants. One source said: 'The firm is a good business but the new owners don't want it.' Already up for sale is Mowlem's Australian rail operation, Barclay Mowlem.
Carillion is understood to be looking to break Mowlem's defence business into two parts because of its size as well as rebrand a number of Mowlem companies with the Carillion name.
The Mowlem name has been in existence since 1822 but the Carillion deal looks to have signalled its gradual phasing out. Those businesses set to be rebranded include facilities management operation Aqumen, but some expect Mowlem's regional construction operations to keep their current names.
The source said: 'Regional construction has got a good name with businesses like Ernest Ireland down in Cornwall so I think the names will stay.' Carillion is due to release its 2005 results on March 8, when it is expected to unveil further details of its plans to mesh the two businesses together.
An integration team has already toured the Mowlem business and managers at Mowlem have met their counterparts at Carillion.
But one insider said: 'One of the problems is a lack of communication.
We've had the integration team around but then we've had human resources around too saying it might be wise to dust down the CV. It's causing a bit of angst.' Mowlem has around 50 principal offices with a host of smaller offices dotted around the country. Its headquarters in Isleworth, west London, employs around 60 people.
Mowlem's 2005 results were due out next month but, under complex financial rules, these will now be filed at Companies House by the end either of July or of October.