China remains the largest creditor of the United States after boosting holdings of US Treasuries by $7.9 billion in October to $1.1615 trillion, the US Treasury Department said on Monday.

But by October, China had made more reductions to its US Treasuries holdings than increases, cutting its total holdings by $4.7 billion from $1.1662 trillion at the start of the year.

Japan, the second-largest foreign holder, bought $5.2 billion in October, taking its total holdings to $1.135 trillion.

While China's net purchases have fallen by about $94 billion in the past 12 months, Japan has boosted its portfolio by around $129 billion in the same period, triggering speculation it could overtake China as the biggest net holder of US Treasuries in 2013.