HOUSTON (AP) _ Continental Airlines says it will offer one-way tickets to and from Texas cities for as low as $9 to fill seats that otherwise would go empty.

The airline said response was brisk, and at least two other carriers were considering today whether to follow the low fare lead.

''It's a whole lot more productive to put somebody in a seat at $9 or $19 than to have that seat go empty,'' said John Nelson, Continental executive vice president of marketing.

The announcement Monday came just days after Continental announced it was raising fares 4 percent.

Dubbed TexSavers, the new fares are good on Tuesday and Wednesday for travel between all Texas cities Continental serves, except El Paso, and for travel between Houston and New Orleans, Oklahoma City and Tulsa.

The fares are expected to increase the carrier's revenue by about $3 million to $4 million a month, Nelson said.

The lowest fare available - $9 one-way - will be for travel from Houston on Tuesdays and Wednesdays to New Orleans and throughout Texas, except El Paso, Nelson said. The cost for travel between Oklahoma City and Tulsa from Houston is $19 one way, and the cost for Texas flights involving El Paso is $39 one way.

The new fares require a 21-day advance purchase, are non-refundable and are subject to availability.

Unrestricted fares are marked at $39, $59 and $79.

''We are having one of the busiest nights ever in Texas,'' Continental spokesman Ned Walker said Monday. ''The phones are ringing off the wall. No one's ever seen fares like this in Texas.''

Southwest Airlines, a no-frills regional carrier based in Dallas, is considering the fares but has not decided whether to match the cuts, said spokesman David Brown. American Airlines also said it is studying the reductions.

Continental and Eastern Airlines are subsidiaries of Houston-based Texas Air Corp., the nation's largest airline company.