March 6 (Bloomberg) -- Lehman Brothers Holdings Inc., the fourth-largest U.S. securities firm by market value, suspended two London-based equity traders after internal controls identified ``issues'' on share valuations.

The sums involved are ``not material,'' an official for the New York-based company said in a phone interview today. The traders were suspended Feb. 28, he added.

The issue is being reviewed in line with normal procedures, according to Lehman. A spokesman for the company declined to comment. Teresa La Thangue, a spokeswoman for the U.K.'s Financial Services Authority, also declined to comment.

Lehman's revenue from equities climbed 76 percent to $6.3 billion last year, accounting for one-third of the total. The firm reports first-quarter earnings March 18.

The firm fell $2.03, or 4.2 percent, to $46.03 at 4 p.m. in New York Stock Exchange composite trading. The 12-member Amex Securities Broker/Dealer Index declined 4.9 percent.

The suspension of the Lehman traders was first reported on the Wall Street Journal's Web site.

To contact the reporter on this story: Joyce Moullakis in London at jmoullakis@bloomberg.net

Last Updated: March 6, 2008 17:01 EST