BEIRUT/AMMAN, April 14 (Reuters) - Saudi Arabia plans to pay off Syria's debts to the World Bank, three people familiar with the matter said, paving the way for the approval of millions of dollars in grants for reconstruction and to support the country's paralysed public sector.

The plans, which have not been previously reported, would be the first known instance of Saudi Arabia providing financing for Syria since rebels toppled former leader Bashar al-Assad last year.

Syria has around $15 million in arrears to the World Bank which must be paid off before the international financial institution can approve grants and provide other forms of assistance.