(Adds more details from prospectus)
CARACAS, Sept 16 (Reuters) - Venezuela's state oil company PDVSA launched on Friday an offer to swap up to $7.1 billion of debt maturing next year for a new 2020 bond with a coupon of 8.5 percent in an effort to ease its heavy short-term payment schedule.
"Holders of eligible bonds, maturing in April and November of 2017, will have 20 days to exercise their option to participate in this excellent investment opportunity," the company added in a statement.
PDVSA, which is the financial motor for the socialist government given that oil accounts for 94 percent of Venezuela's export revenues, added that the 2020 bond would be backed by 50.1 percent of shares in its U.S. refining unit Citgo.
After long fretting about possible default, investors in recent months have grown more optimistic the OPEC member will meet debt payments despite an economic crisis that has spawned triple-digit inflation and chronic product shortages.
President Nicolas Maduro notes the ruling Socialists, in power since Hugo Chavez's government from 1999, have never missed a bond payment and calls default rumors part of a U.S.-backed smear campaign by adversaries to weaken his government.
Amortizations for the 2020 bond will be paid annually over four years, PDVSA added. Its statement can be seen in Spanish here: (tinyurl.com/jg24fd6)
In a prospectus on its web site, PDVSA said the 20 weekdays of the offer would expire on Oct. 14, though the company reserved the right to extend that.
Results would be given on Oct. 17, with the bonds issued on Oct. 19, according to the preliminary timetable. Offers must be over $150,000. The agent in charge of the swap is D.F. King & Co and the fiduciary Union Bank, the prospectus added.
PDVSA said its total debt up to June 30, 2016, stood at $37.3 billion. (Reporting by Diego Ore and Andrew Cawthorne; Editing by Alan Crosby and Diane Craft)