RIYADH- UBS UBSG.S , the world's biggest wealth manager, wants to increase the number of bankers targeting the Middle East notably those serving the Saudi wealth market, an executive said. Simon Smiles, chief investment officer of the bank's ultra high net worth unit, told Reuters at an investment conference in Riyadh that Saudi investors wanted to diversify their assets, which meant more demand for wealth management services.

UBS serves clients from Geneva, Dubai and London. It also has an advisory office in Riyadh. He did not provide details on the hiring figures.

"We continue to see Saudi clients looking to invest both domestically and abroad," Smiles said, after concerns about the kingdom's oil-reliant economy rose while the crude price fell.

Some investor fears were eased in December, when Riyadh released a plan to abolish the deficit by 2020, cutting it from $79 billion or 12.3 percent of gross domestic product in 2016 via steps such as domestic energy price hikes and tax rises.

"The mood definitely appears to have improved but diversification is a natural evolution of an investment portfolio," Smiles said.

For bankers, Saudi Arabia's wealth market offers tremendous potential. The world's biggest oil exporter counts the most billionaires and the richest ones among Arab countries with 10 of having a combined net worth of more than $40 billion.

UBS's Swiss rival Credit Suisse CSGN.S is seeking a banking licence in Saudi Arabia to build an onshore private banking business there.

Citigroup C.N wants to hire up to 20 bankers in Saudi Arabia, where it plans to formally begin operations in the first quarter after obtaining an investment banking licence in the kingdom, a senior executive earlier told Reuters.

(Reporting by Saeed Azhar and Katie Paul; Editing by Edmund Blair) ((Saeed.Azhar@thomsonreuters.com; +971 44536787; Reuters Messaging: saeed.azhar.reuters.com@reuters.net))