* NCB is second bank after Samba to take legal action
* Construction giant's local accounts frozen - sources
* Move threatens 13 bln riyals debt restructuring
By Tom Arnold
DUBAI, Dec 8 (Reuters) - Saudi Oger's attempt to restructure around 13 billion riyals ($3.5 billion) in debts have been dealt another blow after a second major creditor obtained a court order demanding the money it is owed by the construction group, sources said.
Saudi Oger, owned by the family of Lebanese Prime Minister-designate Saad al-Hariri, has for years played a central role in building everything from hotels to hospitals in Saudi Arabia.
But a cut in government spending after a slump in oil prices has left firms like Saudi Oger struggling to service debts.
National Commercial Bank (NCB), Saudi Arabia's largest bank, has obtained a court order against Saudi Oger, the sources told Reuters, following a similar move against Saudi Oger by Samba Financial Group in July.
Their rejection of a so-called standstill requested by Saudi Oger on the money it owes to Saudi banks puts the whole process in doubt as the company would only seek to press ahead with a deal if all banks agreed to the request, the sources said.
A standstill would allow Saudi Oger breathing space to move ahead with one of the largest debt restructuring deals in the Gulf in recent years, giving it more time to collect money owed by the government, they added.
Saudi Oger, NCB and Samba were not available for comment.
One of the sources said NCB had taken the legal action within the last few weeks in a court in Saudi Arabia's second city of Jeddah, where the bank is headquartered.
Reuters was not immediately able to verify the enforcement orders, which mean Saudi Oger has to repay Samba and NCB or risk having assets seized and sold, the sources said.
The moves by NCB and Samba have led to banks being required by the central bank to freeze Saudi Oger's accounts, making it difficult to meet its payments, the sources said.
However, some of the backlog of outstanding wages owed to staff were being paid directly by the government, one added.
Saudi Oger has been seeking to shed assets in order to cut its debts, with Arab Bank Group Chairman Sabih al Masri leading a consortium of other investors in a bid to buy the group's 20 percent stake in Arab Bank. ($1 = 3.7500 riyals) (Editing by Alexander Smith)