BEIJING China's largest private property developer Country Garden Holdings is seeking to add a 40-day grace period for the repayment of a 3.9 billion yuan ($535.3 million) private onshore bond due on Saturday, according to a document seen by Reuters.

The cash-strapped company is also seeking creditors' approval to extend the repayment due Sept. 2 by three years, and it delayed the voting deadline for creditors to approve the new plan by a week to Aug. 31 to garner more support, documents seen by Reuters have shown.

Country Garden did not immediately respond to a request for comment.

The developer earlier this month missed two dollar coupon payments totalling $22.5 million, raising fears that the country's deepening property debt crisis would undermine the financial sector and a broader economic recovery.

In the document received by private bondholders on Tuesday, Country Garden added a new voting item of adding a grace period of 40 calendar days.

A small bondholder, among those who vetoed the repayment extension plan last week, told Reuters he also planned to vote against the proposed new term.

($1 = 7.2856 Chinese yuan)

(Reporting by Kevin Huang in Beijing, Clare Jim in Hong Kong and Li Gu in Shanghai; Editing by Jacqueline Wong and Edmund Klamann)