MILAN (Reuters) - Italian eyewear maker Safilo SpA (SFLG.MI) could bring on board private equity and industrial partners to help solve financial worries, sources said after bankers agreed to a debt payment being delayed.

Safilo said that bankers had agreed to delay to Dec. 31 payment of a financing instalment which was due on June 30.

Safilo, whose net debt reached 618 million euros ($872 million) at the end of March, is in talks to find a partner to strengthen its balance sheet.

The delayed instalment was due under agreements regarding Safilo's existing senior loan. Safilo said it had also won a waiver on financial covenants linked to the same financing arrangement.

Two sources close to the operation told Reuters that two private equity funds -- Bain Capital and Pai Partners -- were in the running to buy stakes in Safilo.

"We are now waiting for exclusive talks to begin with one of the two funds. Around four weeks are still needed to clinch a deal," one of the sources said.

An alternative solution to private equity, proposed by the banks, was to bring on board an industrial partner "which could be Marcolin (MCL.MI), to create a new sort of system which could also involve Tod's (TOD.MI) Della Valle (family), a shareholder of Marcolin," he said.

A second source said the solution could involve bringing on board funds and industrial partners together.

Safilo shares ended up 3.6 percent at 0.4605 euro. (Writing by Stephen Jewkes; Editing by Dan Lalor) ($1 = 0.7087 euro)