BY BEN PROTESS

Stock brokers are on notice to watch what they “tweet.”

Wall Street’s self regulatory organization, the Financial Regulatory Authority, has suspended a California-based broker for sending a series of “misrepresentative and unbalanced” messages on the microblogging site Twitter. Finra also fined the broker $10,000. Her suspension will last a year.

The case, originally filed in January and released Friday in Finra’s quarterly disciplinary report, is the finance industry’s latest social-media-related brush with the law. Finra has started a social networking task force and the S.E.C. is reportedly looking into the issue as well.

Most Wall Street firms, aiming to avoid the scrutiny, prevent employees from visiting Facebook and Twitter at work. Morgan Stanley’s wealth management division recently said it would allow its nearly 18,000 financial advisers to access Twitter, though all posts must first be approved by the firm.

Finra sanctioned the California broker after she praised certain investments to her 1,400 Twitter followers without notifying her firm of the stock-picking messages. Some of the “overly positive” messages predicted that stocks, including Advanced Micro Devices, would soon surge.

On Sept. 9, 2009, she wrote: “Keep an i on AMD ppl! Just bike abve $5 = margins & institutionals can now ‘play ball!’ Barclay upgraded to $7 ystrdy, but it should be $10+”

A couple months later, she sent: “How accurate am I with AMD? Just check out my tweets! The future of AMD in 2010? Ummm..I would say $12 is conservative!”

The 140 characters allotted by a Twitter message were apparently too abbreviated for the broker. The messages, Finra said, “failed to disclose material information” about her recommendations, including that she held big stakes in some of the investments she was pushing.

The broker’s multimedia misbehavior extended to two Web sites she created, which contained misleading information about her “career accomplishments.”

Finra’s complaint was part of a broader inquiry into her moonlighting as a jewelry executive and translator for a foreign currency trading firm. The broker, according to Finra, failed to tell her firm about the stint as vice president of a jewelry design company and some 13 private brokerage accounts she held.