SAN FRANCISCO (Reuters) - Apple Inc's quarterly revenue and earnings beat Wall Street's targets on surprisingly strong sales of its flagship iPhone, sending its shares up 4 percent.

But profit slid 22 percent in its fiscal third quarter as margins were pressured by growing competition and a wider array of lower-end devices such as older smartphones.

Apple earned $6.9 billion, or $7.47 a share, on revenue of $35.3 billion. That compared with a profit of $8.8 billion, or $9.32 a share, on revenue of about $35 billion in the year-ago quarter.