A Venezuelan judge last month ordered four members of the Sumate civil association - which backed the 2004 referendum against Chavez - tried for conspiracy after they received a grant last year from the National Endowment for Democracy (NED).
The endowment is a non-governmental organisation funded by the US Congress to "promote democracy internationally".
New financing to Sumate could fuel already tense relations between Washington and Chavez, an ally of Cuba's Fidel Castro, a long-time foe of the US.
Chavez brands members of Sumate traitors, while opposition leaders and some US officials say the group has been targeted in a political witch hunt against critics of the former army colonel elected as president.
Sumate has been granted $107,200 by the NED, financing which will go towards a civil-rights and election education campaign, Sumate and the NED said.
"What we are doing is within the framework of the law, and does not violate any regulation. But of course we know that the case against us is political in character," Sumate representative Roberto Abdul said.
The grant, which will help to "strengthen the democratic process in Venezuela" is approved but in the final stages of being signed, NED spokeswoman Jane Riley Jacobsen said.
Earlier this year, a Sumate leader, Maria Corina Machada, held talks with US President George Bush in the White House.
"What we are doing is within the framework of the law, and does not violate any regulation. But of course we know that the case against us is political in character"
The Venezuelan government slammed the meeting as a provocation.
The four Sumate members face up to 16 years in prison if they are convicted. No date has been set for their trial.
Sumate had previously received a $31,000-grant from the NED.
Chavez has lambasted the endowment for backing opponents trying to unseat him.
Threat to democracy
Last month, US Senator John McCain, an Arizona Republican, wrote to Chavez asking him to stop the prosecution of the four Sumate activists in a letter describing the prosecution as a "grave threat to democracy" in Venezuela.
Chavez, a former army paratrooper elected in 1998 vowing to combat poverty, often accuses Washington of trying to topple him and backing a 2002 coup which he survived.
He won the August 2004 referendum, although opponents complained about fraud, a charge international observers did not support.
US officials reject Chavez's plot charges, but they portray him as an authoritarian who undermines democracy at home and destabilises the region by promoting "new socialist" ideas.