A series of 'institutional investors' snapped up 3.8 million shares in the company, which owns Will Alsop's office among many others.
According to a statement, these proceeds will be used to manage the build-up of debt from recent acquisitions.
The deal will further strengthen the company's hand to clear the way for yet more takeovers.
The firm shot to pole position in September, in the race to come top of next year's AJ100, when it took over the Parr Partnership in Scotland.
The business now employs an extraordinary 416 architects, whereas BDP came top of the 2006 survey with 281.
Stewart McColl, SMC's chief executive, commented on the deal: 'The Board is delighted with the level of investor support in the placing, particularly from a number of new institutional investors.
'This strengthening of the balance sheet enables SMC to go forward with its long- term strategy,' he added.