Exponent rises on news of move into S&P index

Exponent shares rise on news it will move into S&P Small Cap 600 index, change set for Sept. 8

• On 2:37 pm EDT, Monday August 31, 2009

NEW YORK (AP) -- Shares of science and engineering company Exponent Inc. jumped Monday after Standard & Poor's said it was substituting the shares for those of Kirby Corp., a boat and diesel engine company, in the S&P SmallCap 600 index.

Menlo Park, Calif.-based Exponent will replace Houston-based Kirby, which will be moved into the S&P MidCap 400 index to replace Airgas Inc. Airgas, in turn, is replacing Cooper Industries Ltd., which is being dropped from the S&P 500 index because it is changing its home base to Ireland, the agency said.

The changes will be effective Sept. 8.

In afternoon trading, shares of Exponent rose $3.20, or 12.6 percent, to $28.60, and Kirby advanced 12 cents to $36.79.