Four U.S. senators are urging the Federal Communications Commission to investigate whether cell phone operators that sell phones on an exclusive basis are unfairly restricting consumer choice.

The senators are asking the FCC to consider, among other things, whether there's too many of these arrangements between dominant U.S. carriers and handset makers, and if they limit a U.S. customers' ability to use their phones for certain features.

The four senators calling for the inquiry - John Kerry, D-Mass., Roger Wicker, R-Miss., Byron Dorgan, D-N.D., and Amy Klobuchar, D-Minn. - did not identify what deals they were alluding to.

AT&T Inc. (T) has an arrangement to exclusively offer the Apple Inc. (AAPL) iPhone in the U.S. Meanwhile, Sprint Nextel Corp. (S) sells the Palm Inc. (PALM) Pre on an exclusive basis as well.

An Apple representative had no comment. A spokesman for AT&T, Sprint and Palm weren't immediately available for comment.

-By Ben Charny; Dow Jones Newswires; 415-765-8230; ben.charny@dowjones.com