• US seeks to lock in group of Venezuelan oilfields to be developed by American companies
• Pact being discussed at high levels in Caracas and Washington
• Deal could raise constitutional questions, face legal challenges

HOUSTON/WASHINGTON, Aug 27 (Reuters) - Trump administration officials are working on a deal to secure long-term access to a portion of Venezuela’s ‌crude reserves, sources with knowledge of the negotiations said on Thursday, a move that could ultimately lower the cost of oil imports.

The agreement, which could be signed and made public soon, is expected to operate in a way that would let the U.S. government lock in a group of Venezuelan oilfields to be developed by American companies, the sources said, ​adding that the resulting supply would be guaranteed for the United States.

“This is real and being discussed at the highest levels of the U.S. ​and Venezuelan governments,” one of the sources said. A separate source said a “lease” was in consideration as the legal model ⁠to make the deal work, with a further auction or tender to allocate each one of the fields among U.S. producers.

A list of 17 fields in ​negotiation seen by Reuters includes green fields in the vast Orinoco Belt combined with mature areas in Lake Maracaibo, some of which are currently operated by ​a small Chinese firm whose contract was signed during Maduro’s administration.

The White House referred questions to the U.S. Department of Energy. Venezuela’s oil ministry, state oil company PDVSA and the Energy Department did not immediately reply to requests for comment. Venezuelan oil minister Paula Henao could not be reached for comment.

Venezuela is considering leaving the OPEC oil production group ​as it strengthens ties with the U.S., Bloomberg reported late on Thursday. Venezuela, which joined the group as a founding member in 1960, has not ​met OPEC quotas for years as its state-run oil industry suffered from neglect and corruption. The U.S. has long been at odds with OPEC for its influence on oil ‌prices. Current hydrocarbons ⁠regulation in Venezuela, which has the world’s largest crude reserves, does not include acreage leases for oil areas, while the Constitution reserves the industry’s core activities to the state.