ROME, May 8 (Xinhua) -- Over 700 flights were cancelled in Italy on Tuesday as around 4,000 air traffic controllers and related workers went on a one-day strike on Tuesday, local media reported.

At least 720 arrivals and departures were cancelled as of Tuesday morning. Alitalia cancelled at least 80 flights out of the Italian capital and over 200 flights overall due to the strike, according to ANSA news agency.

The nationwide action was called because air traffic service provider ENAV S.p.A., which was partially privatized by the economy ministry in 2016 to reduce Italy's public debt, failed to renew a national collective bargaining contract that expired on Dec. 31 of that year, unions said in a joint statement.

Unions argue that while corporate profits rise, the company has failed to reward its labor force, which is under pressure due to increased air traffic and longer overtime demands.

"We are striking to call attention to the fact that management is privileging the interests of investors and financial markets over those of labor," Filt-CGIL union spokesman Guido Barcucci told Xinhua, adding that almost 100 percent of workers represented by his union adhered to the strike.

A look at the company's financials appears to bear this out. In 2017, ENAV reported consolidated net revenue of 881.8 million euros (about one billion U.S. dollars), up 1.9 percent over 2016.

At the same time, labor costs were unchanged at 478.4 million euros. While there was a 6.5-percent increase in wages, this was offset by staff reductions, the company said on its corporate website.

"We are disappointed by the company's behavior," Fit-CISL transport union secretary Salvatore Pellecchia said in a statement. "While continuing to realize profits, management hasn't even bothered to try to avert the strike by calling the parties to the negotiating table."

Almost 175 million passengers transited through Italy's airports in 2017, up 6.2-percent compared to the previous year. Rome's Leonardo da Vinci International Airport led the way with almost 41 million passengers and 23 percent of total traffic, according to the Italian Civil Aviation Authority (ENAC).

ENAV manages 1.86 million flights a year out of 45 civilian airports throughout the country. (1 euro=1.19 U.S. dollar)