Montgomery County businessman Rob Sobhani announced his candidacy for the U.S. Senate yesterday, joining a crowded Republican field by pledging to fight for lower taxes and secure more business for Maryland companies.

In two announcements, the 39-year-old international business consultant outlined a platform he said made him a "caring conservative." He presented his views on a mix of issues that, taken together, place him among the rank of Republicans who believe greater economic opportunity would solve most social problems.

Sobhani said he would support a flat tax rate that would exempt married couples making less than $20,000 a year from all income taxes. He pledged to oppose any move to tax Internet commerce, and he would work to expand the earned income tax credit, allowing the working poor to keep more of their salary.

The son of Iranian immigrants, Sobhani also said he would propose legislation that would make English the nation's official language. He said the law would have the practical effect of requiring all government business to be conducted in English.

"Language is what binds us together," said Sobhani, who speaks five languages himself. "I'm not saying we shouldn't speak Spanish or French. But when we take a driver's test, let's make sure we do it in English. When we pledge allegiance to the flag, let's make sure we do it in English."

Sobhani, who ran unsuccessfully in 1992 for the GOP U.S. Senate nomination, joins five other Republicans who have filed candidacy papers so far. What sets him apart is a fairly healthy campaign account--now at $100,000 and counting--and a finance committee headed by Sheldon Kamins, a Potomac developer and prominent Republican rainmaker.

One Democratic challenger has entered the race for the seat now held by U.S. Sen. Paul S. Sarbanes (D), who is preparing to run for his fifth term.

Sobhani, who has lived in Montgomery for 21 years, said he would not serve more than two terms if elected.

Sobhani holds a doctorate in government from Georgetown University, where he frequently lectures on international relations, particularly American energy policy. He is president of Caspian Energy Consulting, a firm that specializes in helping U.S. companies do business in the Middle East and Caspian region. Citing those contacts and experience, Sobhani pledged to bring in $3 billion worth of new business to Maryland companies during his first term in office. If he fails to meet that goal, he said, he would not seek a second term.

"Politicians in this country talk too much," Sobhani told about 50 supporters gathered at the Cabin John VFW Post. "I'll bring in this business or I don't deserve to be reelected."

CAPTION: Rob Sobhani speaks with a supporter, Simin Barbour of Bethesda, after announcing he's running for the U.S. Senate. He also outlined a platform he said made him a "caring conservative."