KUALA LUMPUR, Jan 17 — Gamuda Bhd and London-based real estate investor Castleforge marked the next stage in their £1.2 billion (RM6.6 billion) redevelopment of 75 London Wall in the City of London with a groundbreaking ceremony and the signing of one of London’s largest property development loan in recent years, valued at £500 million (RM2.75 billion).