(Reuters) - GT Advanced Technologies posted quarterly profit above analysts' estimates for the ninth time in a row, partly helped by better performance at its polysilicon segment, but it cut the upper end of its full-year earnings outlook.

The U.S. solar and LED equipment maker now expects to earn $1.45 to $1.60 per share on revenue of $950 million to $1.05 billion in 2012.

Analysts, on average, were expecting earnings of $1.50 per share on revenue of $995.3 million, according to Thomson Reuters I/B/E/S.

GT Advanced, previously known as GT Solar, posted a net profit of $15.3 million, or 12 cents per share, down from $63.6 million, or 46 cents per share, a year ago.

GT Advanced, which caters to solar and chemical companies, posted 42 percent lower revenue at $153 million.

Analysts had expected a profit of 8 cents a share on revenue of $145.9 million.

They had slashed their expectations by two-thirds after GT predicted a weak third quarter due to anemic demand for its photovoltaic (PV) products.

A dramatic rise in new solar installations in Germany in the fourth quarter and higher prices for polysilicon -- a key raw material -- has raised hopes for global demand to stabilize in 2012.

Merrimack, New Hampshire-based GT Advanced's shares closed at $9.04 on Wednesday on the Nasdaq.

(Reporting by Divya Lad in Bangalore; Editing by Maju Samuel)