A federal appeals court has turned down Qualcomm Inc.'s request to hold off imposition of an injunction against sales of some of the company's cellphone chips, while Qualcomm pursues an appeal of a patent suit won by rival Broadcom Corp.

The U.S. Court of Appeals for the Federal Circuit, without providing details, ruled Tuesday that Qualcomm had not met its burden of proof to win a stay pending appeal of the injunction, which was ordered by federal judge in Santa Ana, Calif. on December 31.

The appeals court also denied a motion for Sprint Nextel Corp. to intervene in the case. The company is among the cellphone carriers potentially affected by the injunction.

A federal jury concluded last year that Qualcomm infringed three Broadcom patents, covering features that include digital-video technology, technology for allowing cellphones to use two or more networks simultaneously as well as a push-to-talk feature for instant communications between phones.

The subsequent injunction by U.S. District Judge James Selna had an immediate effect on U.S. sales of some handsets using Qualcomm chips. But most of the affected products fall under a sunset provision so that the company can continue selling them through January 2009 if it pays royalties to Broadcom. Qualcomm has been working on technical changes to some products to avoid infringing the Broadcom patents.

A Qualcomm spokeswoman, in a prepared statement, said: "Although our motion for a stay was denied, the Federal Circuit has recognized the need for speedy resolution of the many issues raised by the verdict and remedy in this case, and has therefore granted Qualcomm's motion for an expedited schedule for briefings and oral argument."

The reliability of crime labs has been questioned in several states and at the federal level in recent years.

State and federal courts have come to different conclusions about whether recent Supreme Court decisions affirming the constitutional right of a defendant to confront his accusers extend to lab reports that are used in many drug and other cases.

The case the justices accepted, and will consider in the fall, comes from Massachusetts. Luis Melendez-Diaz was convicted of trafficking in cocaine partly on the basis of a crime lab analysis that confirmed that cocaine was in plastic bags found in the car in which Melendez-Diaz was riding.

Rather than accept the report, however, Melendez-Diaz objected that he should be allowed to question the person who prepared it about testing methods, how the evidence was preserved and a host of other issues.