The summit, held as France's unemployment remains stubbornly at twelve-year highs, brought together union leaders, business representatives and ministers.
"The gravity of the crisis obliges us to make decisions," Sarkozy told them, according to a text provided by his office.
A package of measures totalling €429 million ($552 million) was announced at the end of the summit.
These included an extra €290 million for training for part-time workers and the unemployed. There was also a pledge to create an extra 1,000 jobs at the state-run employment agency, Pôle Emploi, costing €39 million.
Companies with fewer than ten employees will be exempt from paying social security charges for any new workers aged under 26-years-old. The measure will cost €100 million.
There were no announcements on controversial plans to reduce employers' social contributions, to be paid for by a hike in VAT. There were also no moves on increasing flexibility by dismantling legislation on the 35-hour-week. Both will have to wait for a televised speech to be given by the president at the end of the month.
Daily newspaper Le Parisien gave its own account of what happened behind closed doors on Wednesday as Sarkozy, prime minister François Fillon and six other ministers met some of France's biggest union barons.
"I'm well aware that at the end of this meeting we're unlikely to be agreed on everything," the newspaper reported Sarkozy as saying, before union leaders weighed in with their own concerns.
Francois Chérèque of the CFDT union was reported as saying it was not possible to create a social "big bang" on the back of an envelope in just three hours.
"Are you paying the ratings agencies for advice?" allegedly asked Bernard Thibault of the CGT union.
"No," replied Sarkozy. "The main agency is Moody's. They carry twice the weight of the others who behave like cowboys."
Thibault later told reporters the measures would have "no real impact on the employment situation today," with 9.8 percent of the workforce out of a job, a 12-year high.
The head of work institute, l'Institut Supérieur du Travail, said on Thursday morning that the summit was a "piece of theatre."
"In the sense that everything is programmed and the texts are prepared," said Bernard Vivier on radio station Europe 1. "The advisers and ministers prepare the summit and then the president arrives to play the principal role for four hours."
"The point of such a summit isn't to negotiate but for the government to get a sense of the collective reactions of the social partners and to change their target," he added.
Socialist presidential contender François Hollande plans to outline the opposition's economic programme in a speech on Sunday.