UPDATE 1-Ametek Q4 beats Street, sees strong 2012

Jan 26 (Reuters) - Diversified manufacturer Ametek Inc posted a quarterly profit that beat market estimates and forecast a strong 2012, helped by strong sales at its electronic instruments group.

The company, which separately said it acquired privately held O'Brien, forecast a 2012 profit of $2.65 to $2.70 per share.

Analysts were expecting earnings of $2.64 per share, according to Thomson Reuters I/B/E/S.

Fourth-quarter net income was $101.9 million, or 63 cents a share, compared with $81.2 million, or 50 cents a share, a year ago.

Revenue rose 13 percent to $762.8 million.

Electronic instruments group sales jumped about 17 percent to $441.5 million.

Analysts, on average, had expected fourth-quarter earnings of 61 cents a share, before special items, on revenue of $765.05 million.

Ametek, which makes display and monitoring devices, and electric motors for vacuum cleaners and blowers, bought St. Louis, Missouri-based O'Brien for about $175 million from Industrial Growth Partners.

"Combined with our analytical instrument solutions, Ametek now can offer its customers a complete solution for most of their process analysis needs," Ametek CEO Frank Hermance said in a statement.

O'Brien, which has annual sales of about $80 million, is a manufacturer of fluid and gas handling products, with operations in St.Louis, Carson city, Nevada and Shanghai, China.

Shares of the company closed at $46.83 on Wednesday on the New York Stock Exchange.