By Poornima Gupta and Lisa Richwine

(Reuters) - Apple Inc closed its stores across the United States on Wednesday for several hours to commemorate co-founder Steve Jobs, who died two weeks ago.

Apple's retail stores were shuttered, with their signature tall glass windows covered with white sheets to keep the proceedings private from outside eyes.

In addition to the closings, the company published a "Remembering Steve" page on the Internet, compiling more than 1 million email tributes it has received since Jobs died.

Inside the closed stores, employees were using the time to watch a broadcast of an event celebrating his life, held at an outdoor amphitheater at Apple's headquarters in Cupertino, California, according to a source familiar with the plans.

Pop star Norah Jones and British band Coldplay performed at the employee event in California, according to the source.

Stores in California were closed from 9 a.m. PDT to noon PDT, according to posted signs. The employee celebration in Cupertino was held from 10 a.m. PT to 11:30 a.m. PT.

It followed a private memorial service for Jobs last Sunday at Stanford University that was attended by Silicon Valley luminaries, politicians and celebrities.

Former President Bill Clinton, News Corp Chief Digital Officer Jon Miller and U2 frontman Bono were among those who attended the private memorial.

Jobs died on October 5 at age 56, after years of suffering from a rare form of pancreatic cancer. Chief Executive Tim Cook said in a memo to employees on October 10 that a celebration of his life would be held Wednesday.

(Reporting by Lisa Richwine in Los Angeles and Poornima Gupta in San Francisco; Editing by Robert MacMillan, Gary Hill)