British Land is mulling whether to open up bids to other contractors on its £400m Euston Tower scheme on which Lendlease has been carrying out pre-construction work for over a year.

Building understands the developer is exploring its options about who to appoint under a pre-construction services agreement for the job.

It is believed to have been in touch with rival contractors about how they would carry out the work on the building which was built in 1970.

How the proposed revamp will look

Lendlease, which was put up for sale in May by its Australian parent, has been carrying out pre-construction work for British Land and continues to do so as part of the planning application which went int to Camden council earlier this year.

It is understood no decision has yet been made on how the job will be procured with British Land thought to be keeping its options open.

Firms that have worked extensively with the developer in recent years include Mace, the contractor behind the new UBS headquarters at 5 Broadgate in the City, and Sir Robert McAlpine, which is building the 2 Finsbury Square tower also in Broadgate.

Others likely to be interested in Euston Tower would include McLaren, which is building a last-mile logistics hub for British Land, and Multiplex which is believed to have never worked with the developer before but is set to carry out a major refurbishment of the former Deutsche Bank headquarters at 75 London Wall.

The work at Euston Tower will see the building stripped back to its core and increased in size from 320,000 sq ft to 500,000 sq ft. It will also retain the foundations and basement.

As well as Lendlease, which redeveloped the nearby One Triton Square for British Land a few years ago, other members of the project team include QS and project manager Gardiner & Theobald, executive architect Adamson, planning consultant Gerald Eve, M&E consultant Arup and sustainability consultants Buro Happold and GXN.

The scheme was built in 1970 and has been empty for the past three years

The latter is a sister firm of architect 3XN, the Danish practice which has drawn up the proposal for the revamped tower and is also working on 2 Finsbury Avenue.

The 36-storey Euston Tower has recently been occupied by HMRC while previous tenants have included Atkins. It has been vacant for around three years. Designed by Sidney Kaye, it was also once home to Capital Radio, now based in Leicester Square.

British Land has previously described the tower as the “gateway” to its Regent’s Place campus.