The studies for the configuration of the Storage plant commenced in the last quarter of 1992, it being decided in 1993 that the final location would be at Aveiras de Cima after the other two alternatives at Carregado and Bemposta (near Alenquer) were rejected.

On 20th April 1994, CLC was constitued, by Petrogal, with a share capital stock six hundred thousand million escudos, which was later increased to five thousand million escudos (25.000.000 euros).

In October 1996, Petrogal sold 35% of CLC's share capital stock being distributed as follows: 15% to Shell Overseas Holdings, Ltd; 15% to Mobil Oil Portugal Ltd, and 5% to BP Portugal Lda.

Later, in the year 2000 BP Portugal S.A. aquired Mobil Oil Portuguesa S.A.'s position in CLC, leaving the distribution as follows: 65% to Petrogal S.A., 20% to BP Portugal S.A. and 15% to Shell Overseas Holding Limited.