HOUSTON, March 6 (Reuters) - A unit in Colombia of Canada's oil firm Pacific Rubiales Energy launched a tender to sell one 1-million-barrel cargo of heavy Castilla crude and one 500,000-barrel cargo of medium Vasconia crude for delivery in April, said an invitation seen by Reuters on Thursday.
Earlier this month Pacific offered two cargoes of Castilla crude that will also be delivered in April. The company is increasing sales of Colombian crudes on the open market since it bought Petrominerales last year, another firm working in the Andean country.
The first cargo, containing Castilla crude, should be loaded at Covenas port on April 7 to 11, while the second one, containing Vasconia, will be delivered on April 11 to 15.
The company said it will receive offers for both cargoes until March 11 and they must be indexed to WTI or Brent front month prices. Sellers will include any combination of Pacific's subsidiaries.