UPDATE 1-Simmons has until June 13 to cure defaults

LOS ANGELES, April 20 (Reuters) - Bondholders have notified Simmons Co that it is in default for failing to make timely financial reports to regulators, the privately held mattress maker said in a filing on Monday.

Simmons said it received a notice sent on behalf of the bondholders -- who claim to own 25 percent of Simmons' $269 million senior discount notes -- that it has until June 13 to file its quarterly report for the period ended Sept. 27, 2008, as well as its annual report for the period ended Dec. 27, 2008.

If Simmons fails to "cure" the defaults by June 13, 2009, forebearance periods on the company's $540 million senior credit facility and $200 million senior subordinated notes will terminate, according to the filing.

Simmons said it intends to cure the defaults by the June 13 deadline. (Reporting by Lisa Baertlein; Editing by Steve Orlofsky)