Trex Co., the nation's largest maker of simulated wood decking, said an expanded advertising campaign during the second quarter helped push sales up 40 percent over the same period last year.

The Winchester company said earnings rose to $11.1 million (75 cents a share) from $6.5 million (44 cents) in the year-ago period while revenue rose to $83.4 million from $59.2 million.

For the first half of 2004, earnings rose to $20.4 million ($1.38) from $16.6 million ($1.13) in the first half of 2003. Revenue rose to $159.7 million from $127.9 million during that period.

* Gene Logic Inc., a Gaithersburg supplier of genetic information to drug companies, said companies were slower to start new drug studies than expected, cutting into second-quarter revenue.

The company's second-quarter loss broadened to $4.4 million (14 cents a share) from $4 million (13 cents) in the same period a year ago. Revenue fell to $18.6 million from $19.4 million in last year's second quarter.

For the first half of the year, the loss broadened to $9.9 million (32 cents) from $9.8 million (34 cents) in the first six months of 2003. Revenue rose to $38.8 million from $32.2 million.