The timing of the sale is yet to be set, but one of the sources told Reuters that the government - one of Asia's most active sovereign issuers of foreign debt - was waiting for the US debt talks and the euro zone debt crisis to settle before it goes back to the overseas debt market.
The sources did not want to be quoted as the debt sale plan was still being finalised.
The planned issue would be the third for the country since September when it became the first in Asia to join a small club of issuers who have sold bonds abroad in their own currencies.
It sold $1 billion of 10-year global peso bonds in September and $1.25 billion of the same bonds with a 25-year maturity in January. Both were oversubscribed.
Manila wants to cut is dependence on costly foreign borrowing and stretch its debt maturities to better manage its liabilities. A record $7.5 billion domestic debt exchange last month extended the average maturity of local bonds swapped to 18 years from about 5.5 years.
Earlier on Monday, Finance Secretary Cesar Purisima told reporters the central bank's policy-making Monetary Board has approved the government's proposed foreign debt swap plan. He did not elaborate.
Last month, National Treasurer Roberto Tan told reporters the government was considering a possible issue of 15-year bonds for the foreign debt offer.
"It is a maturity that we don't have in the GPN (global peso notes)," he said then.
The government has short-listed six banks to manage the debt offer, namely Citigroup, JP Morgan, Goldman Sachs , HSBC , Standard Chartered Bank , and UBS.
Officials said the government may borrow an additional 85 billion pesos ($2 billion) next year on behalf of state-run firms, such as the Power Sector Assets and Liabilities Management Corp (PSALM), to refinance debt, with the extra borrowing not part of the central government debt.
Budget Secretary Florencio Abad said in a congressional hearing on the 2012 national budget that PSALM has 78 billion pesos in short-term loans falling due in 2012.
In its planned 2012 budget, Manila is aiming to cut its total sovereign debt sales by 4.6 percent from 2011, with foreign debt to be slashed by nearly a third.
Copyright Reuters, 2011