HOUSTON, June 14 (Reuters) - Venezuelan crude oil sales to the United States rose nearly 4 percent in May to 762,000 barrels per day (bpd) after declining since January amid falling output and delays at the country's main oil port, according to Thomson Reuters data on Tuesday.
The United States last month received 47 cargoes of Venezuelan crude, a 3.7 percent increase versus the previous month, but still a 2 percent decline versus May 2015, according to trade flows data made with preliminary figures.
A larger number of shipments of diluted crude oil (DCO) and Merey blend received by PDVSA's customers, including its refining unit Citgo Petroleum, Valero Energy and Phillips 66, contributed to the growth.
A backlog of vessels around PDVSA's main ports started easing in the last week on May, when PDVSA announced it had replaced a damaged loading arm at its Jose terminal. A payment agreement reached in recent days with BP has also allowed tankers to discharge.
But concerns on Venezuela have now switched to the OPEC-member's crude production, which in May declined to 2.37 million bpd, according to figures officially reported by the country, its lowest monthly level since mid-2003.
Venezuela's oil industry is suffering from shortages of spare parts, the retreat of oil services firms due to unpaid bills, maintenance issues, and crime, according to workers, union leaders, and foreign executives.
Since last year, the country has regularly imported light crude to formulate exportable blends. That has allowed PDVSA to feed its Caribbean refineries while sending more Merey crude to the United States and other destinations.
A lower crude processing at PDVSA's domestic refining network, which has been partially working this year, has also left more crude for exports, according to analysts.
Reporting by Marianna Parraga; Editing by Marguerita Choy