State-owned oil giant Petroleos Mexicanos said a $5.1 billion debt-exchange offer had nearly been completed, while the deadline for the few remaining creditors to trade in their 10-year, 30-year and 32-year debt for bonds with an equal coupon and maturity has been extended to Sept. 7.

The debt-exchange offer, according to the prospectus the Mexican company filed with the U.S. Securities and Exchange Commission, was made on July 23 and expired on Aug. 20.

Since about 1 percent the old debt remains outstanding, Pemex has extended the offer to Sept. 7 at 5:00 p.m. local time in New York, "unless we extend it" further, the energy company said.

The debt exchange involved $5.1 billion in bonds originally issued between October 2011 and June of this year: $2.1 billion worth of 10-year notes due in 2022, $1.25 billion of 2041 bonds and $1.75 billion of bonds due in 2044.

At the close of the offer on Aug. 20, bonds worth $5.052 billion had been exchanged, or 99 percent of the total in circulation, Pemex said, citing information provided by Deutsche Bank Trust Company Americas, the exchange agent for the exchange offers.

The coupons and maturity dates of the new bonds are identical to those of the previously issued securities.

"The exchange offers are being made in order to satisfy certain of the issuer's obligations under the Registration Rights Agreements referred to in the prospectus," Pemex said in the securities filing.

Pemex, meanwhile, said it reached a deal re-establishing corporate ties with Mexicana de Lubricantes, or Mexlub, a firm in which it holds a 49 percent equity interest. The agreement comes after several years of legal disputes over financial irregularities at the lubricant maker.

"Management was instructed to take the necessary steps for the re-establishment of corporate and commercial life at Mexicana de Lubricantes, without that implying any type of legal impunity," Pemex said in a statement.

Mexlub, a company founded in 1993 by Impulsora Jalisciense, which holds a 51 percent stake, and Pemex Refinacion, holder of a 49 percent interest, held a monopoly on the sale of lubricants at all service stations nationwide.

It has come under scrutiny for alleged irregularities, including lack of financial transparency, tax evasion and suspected fraudulent transactions.

Pemex ranks as the world's fourth-largest oil producer and 11th-biggest integrated oil and gas company.

The company, which has a monopoly on the production of crude, natural gas and petroleum products in Mexico, accounts for roughly 35 percent of government revenues. EFE