Bondholders have told the group — which defaulted on a deadline to repay 1.7bn yuan ($255.9m) of bonds in May — to provide additional guarantees on its debts if it wants to extend its repayment plans, according to resolutions announced this week by China’s Bank of Communications, the lead underwriter of notes issued in 2010 and 2011.

Group unit Baoding Tianwei Yingli New Energy recently met with holders of 1.4bn