SAN FRANCISCO, July 15 (Reuters) - Intel Corp posted second-quarter net income of $2.8 billion, or 55 cents a share, compared with $2.0 billion, or 39 cents a share, in the year-ago quarter following tentative signs of improvement in demand for personal computers.

Second-quarter revenue was $13.8 billion, compared with $12.8 billion in the year-ago quarter, Intel said in a statement on Tuesday. In June, Intel revised increased its second-quarter revenue outlook to $13.7 billion, plus or minus $300 million, citing stronger-than-expected demand for PCs used by businesses.

(Reporting by Noel Randewich; Editing by Steve Orlofsky)