The funding package, launched in co-operation with London mayor Boris Johnson and housing association London & Quadrant, will aim to deliver 2,900 new affordable homes across a range of sites.
Some £42m out of the funding pot will help L&Q deliver 500 homes under its Up2U scheme.
This will offer tenants a discounted rent at 80% of the market rate in order to help prospective buyers save for a deposit.
The announcement of the funding package is set to trigger a further 900 affordable homes to rent on the sites concerned.
The remaining £93m will go towards kick-starting construction at five stalled development sites over the next 12 months.
Once completed the sites will account for an additional 1,500 homes, with a longer term-potential to provide another 6,000 units.
Boris Johnson, mayor of London, says: “The money we are investing today is a major shot in the arm for London’s development sector and for the economy.”
Sir Bob Kerslake, chief executive of the HCA, says: “Our flexible investment approach means we’re able to respond quickly and effectively to bring forward affordable housing that would otherwise not get built.”
David Montague, chief executive at L&Q, says the Up2U product helps to restore the lack of buyer confidence by giving customers choice.
He says: “If consumers prefer not to buy now, they can pay a sub-market rent for as long as they wish.
“They can buy some of their home at a time of their choosing and pay a rent for the part they don’t own. Or they can buy outright.
“It is a straightforward offer which places the choice with the customer.”