Carstens says that some 10,000 of the recently busted company's employees, or about 22 percent of the total, will be eligible for rehire. According to El Universal, a payroll of 8,500 is sufficient to run the company, which means that it had 600 percent of the staff necessary. Carstens also said that paying for the severance packages for the rest will cost from around $1 to $1.5 billion.
Calderón made a prime-time address to the nation to explain his decision, which he justified on mostly economic terms. That was an odd choice; he should have explained the move as more closely related to the union's chicanery. Most people assume such was the real motivation, and it's a legitimate reason. Instead, he made a somewhat disingenuous case that came across as arbitrary (is Luz y Fuerza more inefficient than Pemex, for example?).
[Edited from original form, see comments.]