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June 19 (Reuters) - Oppenheimer & Co downgraded Synaptics Inc (SYNA.O: Quote, Profile, Research), a maker of touch-screen user interfaces, saying the competitive pricing of Apple Inc's (AAPL.O: Quote, Profile, Research) new iPhones will limit the company's ability to tap potential customers looking to launch iPhone killers, sending its shares down 9 percent.

The brokerage cut its rating on the stock to "perform" from "outperform," and removed its price target of $35, saying that it expects the shares to fall to low $30s.

The brokerage said Synaptics shares have been rising on hopes of becoming a key supplier to other iPhone-like devices.

But a cheaper iPhone would force Apple's competitors to rethink their strategy as they will be forced to sell their devices at a lower, less profitable price point.

Oppenheimer also cut its earnings estimates for fiscal 2009 by 6 cents to $2.14 a share and reduced its revenue expectations to $422 million from $428 million.

Oppenheimer was also worried about the company's lack of visibility in the MP3 business.

Synpatics shares were down $2.72 at $39 in afternoon trade on Nasdaq. (Reporting by Kuganandhan Paramanandan in Bangalore; Editing by Anil D'Silva)