DUBAI, Jan 20 (Reuters) - Saudi Arabia's finance ministry has cut advance payments to firms doing construction work for the government to 5 percent of the contract value from 20 percent, a newspaper reported on Wednesday in a fresh sign of a clampdown on state spending.

The ministry has been cutting expenditure and trying to improve efficiency as low oil prices saddle the government with a budget deficit that totalled almost $100 billion last year.

A builder in the kingdom is entitled to an advance payment for certain contracts issued by the government.

This lets the firm move to the construction site, provide early payments to subcontractors and buy equipment from suppliers. The amount is amortised and later deducted from the contract value.

A circular issued by Finance Minister Ibrahim Alassaf reduced advance payments and also specified they should not exceed 50 million riyals ($13.3 million) each, the Saudi-owned al-Hayat newspaper reported.

A ministry spokesman could not be reached for comment.

Saudi construction firms are already under financial pressure from state spending curbs and rising costs for foreign labour. Abdullah Abdul Mohsin al-Khodari and Sons said on Wednesday it made a net loss of 1.04 million riyals in the three months to Dec. 31 compared to a profit of 45.6 million riyals a year earlier. >

(Reporting by Hadeel Al Sayegh; Editing by Andrew Torchia/Keith Weir) ((Hadeel.AlSayegh@thomsonreuters.com; +971566883310;))