SAN FRANCISCO (Reuters) - Apple Inc is facing its first major controversy over well-received voice software Siri, as the cutting-edge iPhone search service ran afoul of abortion rights advocates.

Siri - one of the most popular features of Apple's new iPhone 4S - drew the ire of bloggers and the National Abortion and Reproductive Rights Action League when it could not locate abortion clinics when asked.

NARAL's president, Nancy Keenan, dashed off an email to Apple chief executive officer Tim Cook in which she complained: "In some cases, Siri is not providing your customers with accurate or complete information about women's reproductive-health services."

But Apple said Siri's inability to pull up information was not intentional, blaming the flaw on the fact it was still in beta, or testing, phase.

"Our customers want to use Siri to find out all types of information and while it can find a lot, it doesn't always find what you want," Apple spokeswoman Natalie Harrison said. "These are not intentional omissions meant to offend anyone, it simply means that, as we bring Siri from beta to a final product, we find places where we can do better, and we will in the coming weeks."

Cook responded to Keenan with a similar statement, according to the group's website, which posted the email.