Oilfield services giant Halliburton will make its debut in August at a large Mexican oil basin where its main competitors have already set up shop, according to reports.

Halliburton has won a contract to drill 170 wells for Pemex at Chicontepec starting in the middle of next month, a number of industry executives, who are familiar with the contract, told Dow Jones.

Pemex has also awarded four contracts for about 140 wells each to local drillers, expanding its pool of suppliers for the expensive project.

The new contracts underscore Pemex's efforts to accelerate spending and stabilise falling oil production, down by a fifth since peaking in 2004, Dow Jones said.

During the first half of this year, the company spent only 38% of its exploration and production investment budget.

Halliburton was the only bidder that met the technical requirements for the 170-well contract.

Pemex negotiated with the Houston-based company to lower its price and awarded the contract directly without relaunching the tender to save time, said one of the executives, who declined to be named because he is not authorised to speak to the media.

A Halliburton spokeswoman said the company had no comment.

Pemex did not immediately respond to questions.

Halliburton's main competitor, Schlumberger, has been working with Pemex at Chicontepec since the middle of 2007, and won a second contract to drill 500 wells in March.

Weatherford International has been drilling wells for Pemex at Chicontepec for about a year.

"Mexico will continue to grow as we ramp up new contracts throughout the year," Weatherford executive Bernard Duroc-Danner said in a conference call on Monday.

The executives did not have the value of Halliburton's contract.

Pemex is paying Weatherford and Schlumberger $1.3 million and $1.4 million per well, respectively, for the most recent drilling contracts.

These rates would put the Halliburton contract at over $220 million.

Pemex designed the four 140-well contracts to include local companies.

Mexico has a strong tradition of oil nationalism, and the heavy presence of foreign oil service companies at Chicontepec has raised criticism from opposition lawmakers.

Pemex officials have said they are making an effort to increase business with local suppliers.

Among the companies awarded the contracts is Servicios Integrales, a unit of industrial conglomerate Grupo Carso, which is owned by Mexican tycoon Carlos Slim.

At the start of this year Pemex announced $2.3 billion this year in planned investments at Chicontepec.

Pemex expects Chicontepec to pump 40,000 barrels per day in August and 60,000 bpd by the end of the year.

Weatherford fell behind on two contracts for a total of 600 wells it won in the middle of last year.

Weatherford's Duroc-Danner said the company has improved drilling times at Chicontepec by 20%.