DoubleClick Inc., the No. 1 Internet advertising company, settled a patent infringement suit against rival L90 Inc. The suit claimed that Santa Monica-based L90 infringed on DoubleClick's patented DART system, which sends ads directly to a user's Internet browser. A trial had been set to begin Monday morning, but the companies reached the agreement over the weekend, an attorney for DoubleClick said. Details were not immediately available. A DoubleClick spokesman declined to comment, and an L90 spokeswoman did not immediately return a telephone call. DoubleClick settled a similar patent-infringement claim against Sabela Media Inc., a unit of 24/7 Media Inc., about two weeks ago, the attorney said. DoubleClick shares fell $1.44 to close at $19.25, while L90 closed unchanged at $6.25, both on Nasdaq.