At least 19 people are known to taken their lives in 2008 and 2009 as the company cut thousands of jobs.
Judicial sources say the company and ex-boss Didier Lombard are suspected of using a policy of unsettling staff to speed up job losses.
France Telecom became Orange in 2013.
It will now be up to an examining judge to decide whether or not to order a trial. But if it goes ahead it would be the first trial in France for bullying (moral harassment) of such a large company.
As well as the former CEO, other figures could also face trial including his right-hand man Louis-Pierre Wenes, human resources head Olivier Barberot and four other directors.
In 2006, Mr Lombard announced plans to cut 22,000 jobs and move another 14,000 workers, as France Telecom pushed for greater efficiency in the wake of privatisation two years earlier.
According to an internal document cited by French media, he told a high-level meeting that he would "do it one way or another, through the window or through the door".
In submissions made late last month, the Paris prosecutor accuses France Telecom of enacting a policy in 2007 that resulted in unsettling workers and creating a "professional climate that provoked anxiety" at the time of a "delicate restructuring" of the company, a judicial source told AFP news agency.
The true number of suicides involving staff is unclear, but 60 people are thought to have taken their lives over a three-year period, and unions say as many as 35 died in 2008 and 2009.
Officials speak of 19 deaths during the two years, 12 attempted suicides and eight other cases involving depression or related illnesses.
Although the suicide rate at France Telecom was similar to the national average, many of those who died left notes blaming pressure from management.
Mr Lombard accepted the restructuring upset employees but he has rejected the idea that it led to people taking their own lives.
France Telecom, and later Orange, has been beset by tragedy since 2007:
The spate of work-related deaths was not confined to France Telecom. In 2007, car-maker Renault was investigated after three workers took their own lives.
Under French law, anyone who harasses another with repeated actions with the aim or the effect of degrading working conditions is liable to a year in jail and a fine of €15,000 ($16,500; £12,800).

Lesley Griffiths said the risk would not fall in coming weeks, and spring wild bird migration could increase the chances of further cases.
On Monday it was confirmed that a wild duck died from the disease in Conwy, following cases in south Wales.
On Tuesday, Ms Griffiths told AMs that more cases were likely to be found.
Public health officials have stressed that the risk to humans is "very low".
Ms Griffiths previously announced the extension of an all-Wales avian flu prevention zone until 28 February 2017.
Similar measures have been introduced in England, Scotland and Northern Ireland.
"Work is in hand, with Defra and the Scottish Government, to consider what the exit strategy might be for lifting the prevention zone," she said in a statement.
"I cannot stress enough the need for those who keep poultry flocks and other domestic birds to remain alert for signs of the disease, to contact their private veterinarians if they have any concerns and to practice the highest levels of biosecurity," Ms Griffiths added.
After a lengthy inquiry into a wave of suicides at France Telecom, the Paris prosecutor has recommended that its former chief executive and other key figures are put on trial for bullying.
[NEXT_CONCEPT]
The risk of more cases of avian flu in poultry and other captive birds may increase in the weeks ahead, Wales' rural affairs secretary has warned.