HOUSTON, March 22 (Reuters) -- The refinery in Aruba plans to start hiring workers in April to repair and upgrade the 235,000-bpd plant, while its proposed new operator, Citgo Petroleum, continues talks with the government to sign a contract to lease the idled facility, sources close to the deal told Reuters.

Talks between Citgo -- the US refining unit of Venezuela's PDVSA's -- and Aruba's government started last year for an agreement on a 25-year lease. A memorandum of understanding was signed in September in Houston, where Citgo is based, to explore upgrading and restarting the facility.

Talks between the parties have progressed, one of the sources said, but they are far from setting a date to begin restarting the refinery, which could last up to two years before production resumes for the first time since 2012.

Aruba's Prime Minister Mike Eman told journalists last week that talks continued, but he declined to elaborate as details could not be provided in the middle of negotiations.

A team of Citgo technicians has been working since 2015 on a plan to restart and upgrade the plant. Catalysts used at Aruba's hydrodesulfurization unit (HDS) were removed several weeks ago, according to a source from the refinery.

Former operator Valero Energy halted Aruba in 2012, keeping only its storage terminal operating, and in 2014, it classified it as "abandoned." The US company paid $465 million when it bought the refinery in 2004.