(Updates with Maduro quote, context on bills)
CARACAS, Dec 29 (Reuters) - Venezuelan President Nicolas Maduro on Thursday said his government would extend the use of 100-bolivar notes to Jan. 20, after a plan to withdraw those bills from the economy sparked nationwide protests and widespread looting.
Maduro in December said the notes, the highest denomination bill in the inflation-plagued OPEC nation, would be withdrawn to prevent smugglers and "mafias" from trafficking the bills across the border to neighboring Colombia.
He earlier had postponed the measure to Jan 2. from around mid-December after angry citizens, unable to make purchases and worried they would lose their cash holdings, staged protests that led to hundreds of arrests.
"I want to announce that I have decided to publish a decree extending the validity of 100-bolivar notes until Jan. 20," Maduro said in a televised address.
Venezuela suffers from triple-digit inflation as a result of low oil prices and an unraveling socialist economy, which has left basic purchases, such as a few days' worth of groceries, requiring sacks of cash.
Though many Venezuelans shop with debit cards to avoid the hassle of bills, point-of-sale networks have been increasingly strained and such services are often unavailable in the provinces and poor neighborhoods of the capital.
The 100-bolivar note is worth only around $0.03 on the black market for dollars.
The government has promised to bring in new bills ranging from 500 bolivars to 20,000 bolivars, but merchants and shoppers say they have yet to see them.
Maduro on Thursday said a cargo of the new bills had reached Venezuela's main airport, and repeated accusations that a campaign of sabotage by adversaries had delayed their delivery.
Opposition leaders slammed the measure as a sign of Maduro's economic incompetence and demanded his resignation. (Reporting by Brian Ellsworth; Editing by Bernadette Baum)