The Fed's new bond buying spree will include $40 billion of troubled mortgage-backed securities a month.

In conjunction with its previous stimulus activity, the central bank expects its holdings of long-term securities will consequently increase by $85 billion for each month through to the end of the year.

The bank did not rule out further stimulus measures either.

"If the outlook for the labour market does not improve substantially, the committee will continue its purchases of agency mortgage-backed securities, undertake additional asset purchases and employ its other policy tools as appropriate until such improvement is achieved in a context of price stability," the FRB said yesterday.

The forthcoming boost to global money supply has already lifted key PNG commodity prices for the overall week.

Spot gold is trading around $1773.60 an ounce in the past 30 minutes - up 2% from the close of last Friday.

Singapore Tapis crude closed at $121.36 a barrel overnight which was a gain of $2 or 1.7% from the end of last week.

London Metal Exchange cash copper closed at $8059.25 a tonne last night - 1.3% higher than last Friday.

By the same comparison LME spot nickel rose 1.6% to $16,703.5/t last night.

Coppermoly was the standout performer this week with a 48% gain by early afternoon (AEST).