CARACAS, June 29 (Reuters) - Venezuela's state company PDVSA has suspended gasoline production at the country's second largest refinery due to an outage at its reformer, five sources with knowledge of the operations said on Wednesday.

An intermittent scarcity of fuel has hit the South American country in recent years as PDVSA's aging refineries operate at a fraction of its 1.3 million barrel per day (bpd) joint capacity and U.S. sanctions block the arrival of imported gasoline.

The Cardon refinery's naphtha reformer, which produces high-octane components for gasoline, is key for fuel production in the OPEC-member nation. The unit will be out of service while in maintenance, planned to last 18-21 days, the sources said.

"This is an unplanned maintenance program for repairs in the refomer's reactors," one of the people said.

The 310,000-bpd Cardon refinery is part of the 955,000-bpd Paraguana Refining Center on Venezuela's Western coast.

PDVSA did not immediately reply to a request fort comment.

At the neighboring 645,000-bpd Amuay refinery, PDVSA's largest facility, the catalytic cracker was in service on Wednesday, processing 60,000 bpd to allow some 38,000 bpd of naphtha output.

Paraguana, which is working at less than a quarter of its installed capacity, was this week converting Amuay's 38,000 bpd of naphtha output and available inventories of components into some 80,000 barrels of gasoline for domestic distribution.

The 187,000-bpd Puerto la Cruz refinery on the east coast was producing some 18,000 bpd of high-octane gasoline, according to two separate sources.

Venezuela's smallest refinery, the 146,000-bpd El Palito, has not producing gasoline since late 2021 amid an expansion and repair project agreed by Venezuela and Iran. (Reporting by Mircely Guanipa in Maracay and Deisy Buitrago in Caracas Editing by Marguerita Choy)