(Recasts with trading details)
By Deisy Buitrago and Andrew Cawthorne
CARACAS, March 24 (Reuters) - Venezuela launched a new foreign exchange system on Monday that offered dollars at a rate near the black market level, participants said, in an effort to tame the illegal trade and boost flows to local businesses.
Private bank operators said the price for dollars on the inaugural day of the Sicad 2 system varied between 50 and 55 bolivars, with demand high but offer very thin.
"I think the market will get going properly on Tuesday," one trader said, asking not to be named.
The new platform adds a third exchange rate to 11-year-old currency controls that sell dollars at 6.3 bolivars for preferential goods and around 11 bolivars for other items.
Greenbacks currently fetch around 57-58 bolivars on the black market. That price has fallen from 85 a couple of weeks ago on expectations of greater dollar flows via Sicad 2.
In 2003, Maduro's predecessor, the late Hugo Chavez, set up currency controls in a socialist-style overhaul of the economy that he said would channel more wealth to workers rather than to wealthy people with bank accounts abroad.
Critics say the controls spawned corruption, curtailed business, and gave birth to the black market for dollars.
Wall Street economists and bondholders welcomed the new system as a much-needed easing of controls, though they want Maduro to go further across the economy.
Most Venezuelan bond prices were up on Monday, with the benchmark sovereign global 2027 gaining 1.77 percent to a bid price of 76.383.
Trading takes place daily up to 1 p.m. local time (1730 GMT) with the bank due to announce the average price afterwards.
"It is going to cover 7, 8 percent of real (dollar) demands, seeking equilibrium as regards the flow of foreign currency necessary for the functioning of the economy," Maduro said in a speech on Friday.
Sicad 2 essentially revives a previous system, known locally as the "permuta" or "swap" market, which Chavez shuttered in 2010 after accusing speculators of manipulating it.
Opposition politicians have long criticized the government's currency controls. Still, they are lambasting Maduro for what they call a "stealth devaluation" via the new system.
"Today will be 'black Monday'. Sicad 2 is another devaluation for our currency," Tweeted opposition leader Henrique Capriles. "Nicolas has also finished off the bolivar. Another blow to the poor."
Venezuela's annual inflation rate, currently at more than 56 percent, is the highest in the Americas. (Editing by Daniel Wallis, Paul Simao, David Gregorio and Tom Brown)