Updated

The Mexican Senate is debating the final legislation needed to open the state-run oil industry to foreign and private companies.

The Senate is expected to vote in the coming hours on the final two packages of laws to regulate private oil and gas drilling, allowed for the first time since the industry was nationalized in 1938.

Legislators have already approved several laws implementing the 2013 constitutional reforms that the government says are needed to reverse declining oil production by spurring deep-sea and shale gas exploration.

The measures being debated Wednesday are among the most controversial, including a proposal to transfer part of the state oil company's pension debts to the books of the federal government.

Approval is expected, despite objections from those who claim the law privatizes the energy sector.