Private equity firm Kohlberg & Co. ended its campaign to acquire Steinway Musical Instruments after refusing to raise its bid to beat a rival offer, Steinway said in a regulatory filing Tuesday. Kohlberg, which in July proposed buying the iconic 160-year old piano maker for $438 million, waived its right to propose a new bid after the competing proposal surfaced from an undisclosed firm, Steinway said in a securities filing. The disclosure comes one day after Steinway announced that it received a second bid of $38 per share, topping Kohlberg\'s $35 per share offer. The identity of the second bidder was not released. Steinway said the bid came from \"an affiliate of an investment firm with over $15 billion under management.\" The Wall Street Journal, citing people familiar with the matter, said the new bidder is hedge fund Paulson & Co. Steinway has said a buyout would help it build its global business without diminishing the legendary quality of its pianos, renowned for their sound and touch. Steinway shares were off 3.3 percent to $38.30 at mid-afternoon.