By Pesha Magid, Hadeel Al Sayegh and Federico Maccioni RIYADH/DUBAI (Reuters) -Saudi Arabia has scaled back lofty ambitions for its NEOM gigaproject to prioritize completing elements essential to hosting global sporting events over the next decade as rising costs weigh,

The authoritarian country is spending billions on international athletics, from Formula 1 to combat sports, to boost its bottom line and image.

Longtime CEO Nadhmi al-Nasr left Neom, Saudi Arabia’s marquee development, which has been plagued by delays, cost overruns and staff turnover.

Nasr, the long-time chief executive of the $500 billion NEOM mega-project at the heart of Saudi Arabia's drive to diversify away from oil, has departed, NEOM said on Tuesday without giving a reason.

Saudi Arabia replaced the executive that was overseeing its plan to build the $1.5 trillion futuristic development known as Neom, in the latest sign that the project is struggling to deliver on its ambitions.

The departure of the longtime CEO marks a major shakeup at Neom, which is a showpiece of Riyadh’s economic ambitions.