RIYADH (Reuters) - Saudi Arabia will auction real estate owned by indebted billionaire Maan al-Sanea and his company starting next month to help repay billions of riyals due to creditors, sources familiar with the matter told Reuters.

FILE PHOTO: A property belonging to billionaire Maan al-Sanea is seen in Khobar in Saudi Arabia's Eastern Province February 26, 2018. REUTERS/Zuhair Al-Traifi/File Photo

Sanea, ranked by Forbes in 2007 as one of the world’s 100 richest people, was detained last year for unpaid debts dating back to 2009 when his company, Saad Group, defaulted.

His case is separate from the scores of Saudi businessmen and prominent figures who were held on corruption charges last year at Riyadh’s Ritz Carlton hotel, although it touches on similar investor concerns about corporate governance.

In what was Saudi Arabia’s longest-running debt dispute, creditors have spent the past nine years pursuing Saad Group, which is based in the Eastern Province, for debt repayment.

Etqaan Alliance, the consortium appointed late last year by a three-judge tribunal to resolve Saad’s debt dispute, will sell the assets over five months at auctions in the Eastern Province, Riyadh and Jeddah, according to two sources familiar with the matter.

The first auction - of undeveloped and commercial land plots, a farm, and income-generating residential buildings in Eastern Province’s Khobar and Dammam - will take place in late October, the sources added.

One source estimated sale proceeds at one to two billion riyals ($267-$533 million).

A creditor source said the auction had been delayed because of weakness in the local property market.

In March, Etqaan launched the first phase of the auction with around 900 vehicles owned by Saad Group, including trucks, buses, diggers, forklift trucks and golf carts.

That auction raised around 125 million riyals, which went to repay some creditors, including unpaid workers. Proceeds from upcoming auctions will go to 34 creditors, mostly banks, the sources said.

It is unclear whether Sanea, who remains in detention, will be released after his assets are sold.

Saad Group, with interests spanning banking to healthcare, defaulted together with Ahmad Hamad al-Gosaibi and Brothers (AHAB) in 2009, leaving banks with unpaid debt of about $22 billion in what was Saudi Arabia’s biggest financial meltdown.

Earlier this year, Reemas, a financial consultancy advising al-Sanea, reached out to some creditors to try to agree to a settlement that could involve swapping creditor debts for real estate assets, but the terms are still under negotiation.

Local, regional and international banks eligible for a settlement have claims totaling 16 billion riyals, with international banks such as BNP Paribas BNPP.PA and Citi C.N, and regional lenders such as Mashreq, having claims of over 1 billion riyals each, sources told Reuters previously.

Some observers estimate Saad’s total debt to be between 40 billion and 60 billion riyals.

($1 = 3.75 Saudi Riyals)