Shares of PMC-Sierra ( PMCS) rose in after-hours trading Tuesday after the specialty chipmaker said first-quarter revenue will be at the high end of guidance. PMC-Sierra shares were recently up 42 cents, or 2.6%, to $16.36; the stock declined 26 cents, or 1.6%, to $15.94 in Tuesday's regular session. Santa Clara, Calif.-based PMC-Sierra said first-quarter revenue will be above the midpoint of its previously established range of $77 million to $79 million, or 10% to 12% higher on a sequential basis. Analysts currently expect the company to post revenue of $78.17 million in the quarter, according to Reuters Research. The company also said its March quarter book-to-bill ratio already exceeds 1.0, indicating rising orders.