Everybody's been acting jaded about the

Dow Jones Industrial Average

hitting 10,000, but cheers broke out nonetheless on the floor of the

New York Stock Exchange

as the index breached the mark for the first time on an intraday basis at 9:50 a.m. EST.

Ironically, it was one of the Dow's worse performers,

Union Carbide

(UK)

, that pushed the average through the milestone. Carbide said today that its first-quarter earnings would come in around 47 cents a share -- 13 cents better than the

First Call

consensus estimate. Up 2 5/16 to 45 13/16, Carbide accounted for 10.27 points of the Dow.

Also helping the Dow clear the milestone was a strong performance from

Merck

(MRK) - Get Report

. Up 1 3/8 to 85 5/8, the drug maker was adding 6.11 points to the index.

The Dow lately was up 14 to 9973, having peaked at 10,001.79.