Apple Inc.’s sales for the current fiscal quarter may fail to meet the iPhone and iPad maker’s own forecast as well as Wall Street’s projections, according to Glen Yeung, a Citigroup Inc. analyst.

A Bloomberg chart (included with this story) displays the average second-quarter sales estimates since Nov. 1, a month into the company’s fiscal year, among analysts in a Bloomberg survey.

Citigroup cut its Apple (Nasdaq: AAPL) revenue figure this week by 3.7 percent, to $40.4 billion. Demand is falling for components used in the iPhone 5 and the full-sized iPad, judging by contacts with suppliers, Yeung and two colleagues wrote in a report.

“Share loss by Apple in both the tablet market and the smartphone market” may be behind the drop, they wrote. Yeung, based in San Francisco, reduced sales and earnings projections through fiscal 2015 and lowered a 12-month price estimate for the stock by $20 a share, to $480.

Apple forecast $41 billion to $43 billion in second-quarter revenue on Jan. 23, when the Cupertino, California-based company released first-quarter results. Analysts’ average prediction has held at $42.9 billion since Jan. 28. Forty-two analysts surveyed expect the company to meet or beat its sales estimate.

Yeung is among 11 analysts with some version of a hold rating on Apple, according to data compiled by Bloomberg. The total is the highest in about six years. Fifty others recommend buying the stock, and there are three sell ratings.

Apple Radio Delayed

In other Apple news, the company  delayed the start of an online radio service to compete with Pandora Media Inc. after talks with music labels stalled, according to four people with knowledge of the situation.

The company still seeks to start the advertising-supported radio service by the end of the year, said the people, who asked for anonymity because the plans haven’t been made public. The delay was reported earlier today by the New York Post.