Jan 25 Brazil's lack of clear rules for the unitization of oilfields is delaying the development of as many as 10 billion barrels of oil and gas and about $120 billion of investment, Jorge Camargo, head of Brazil's oil industry association IBP said on Monday.

Unitization, the process of joining different or competing oil rights in an oilfield into a single unit, is required under Brazilian law, but existing regulations have complicated or prevented this from happening, stopping development in some areas, Camargo said in a conference call.

Camargo, who spoke on a conference call with journalists after meeting with Brazilian President Dilma Rousseff today in Brasilia, said he is optimistic she plans to move quickly to fix the unitization rules and present a stimulus package for the industry as its struggles with low prices.