Mace is due to put in its quote for the job this week - believed to be around £400 million on a fixed-price contract - with a decision expected to be made at a board meeting of client Teighmore early next month.
The take-it-or-leave-it offer is the third time Mace has come up with a price on the job - after being forced to amend its original figures when Teighmore sounded out Laing O’Rourke last autumn to come up with an amount that met its budget.
At £400 million, the number is at least £50 million more than the £350 million widely believed to be Mace’s price first time around.
But it is understood this is down from the cost earlier this year, which sources said had escalated to £450 million.
The bid is being submitted to Bernard Ainsworth, the man in charge of the whole development in which the Shard sits - London Bridge Quarter - as well as project manager Turner & Townsend.
One source said: “They will be making some sort of decision by early October.
“They’ve spent so much on demolition already, I can’t see it not going ahead.”
Teighmore has already asked steelwork contractor Cleveland Bridge and cladding firm Scheldebouw to lock down prices for their respective packages ahead of work beginning in earnest next year.
CBUK has begun ordering the first amount of the required 12,000 tonnes of steel from Corus in order to reserve capacity.
Mace’s latest bid comes after months of negotiations to get prices on some of the key subcontract packages down on the 310 m-high building which will go up above London Bridge railway station.
John Doyle has been lined up to carry out the concrete work, which carries a price tag of £50 million over 30 months.
The M&E contract has also caused Teighmore - which is made up of four Qatari banks and Sellar Property Group - problems. Hotchkiss and Phoenix are understood to be lined up for the split deal.
One source said: “Mace has kept shifting around £15 million worth of work between packages. It’s been more of a logistics thing than about saving money.
“I think what Teighmore wants is a set price, rather than needing to know what the price is.”
Piling firm Stent is due to start work on the job at the beginning of next year once Keltbray has completed demolition and groundworks. The building is due to be finished by March 2012.
Analysis: Rejection of bid will raise fresh doubts
By David Rogers
It was nearly eight years ago that Bovis Lend Lease was appointed to project manage construction of the Shard.
A lot has happened since - Wembley Stadium got built; London won the right to host the Olympics - but the Shard has resolutely refused to come out of the ground.
Yes, the building it will replace is being torn down and subbies are finally being appointed to key packages. But no one is craning their necks to peer skywards. Not yet anyway.
While it might not be the end of the line for the job if Mace’s bid gets turned down, the consequences of such a decision would lead more and more to question whether, after nearly a decade in gestation, the thing ever gets off the ground.
Teighmore wants it built by 2012 and it’s easy to see why. The eyes of the world will be on the capital later that summer and the Shard will be a stand-out structure. It would be great if it got built.