North Dakota senators have endorsed a college tuition grant program for resident high school students who score well on a national test, with one lawmaker calling it a needed effort to compete for the state's brightest young people.

"We have suggested for years that the university system is our economic engine," said Sen. Larry Robinson, D-Valley City. "It cannot, and will not, be an economic engine if we don't keep our students."

Dubbed the "promise grant" program by its sponsor, Sen. Tony Grindberg, R-Fargo, the initiative would pay a gradually larger share of the tuition bill for students who meet a residency requirement and academic standards.

To qualify, students would have to attend all four high school grades at a North Dakota private or public school, and attend a North Dakota school during any five years between kindergarten and the eighth grade.

Students would need a minimum composite score of 23 on the national ACT test - the average North Dakota score last year was 21.4 - and have at least four units each of science and higher-level math, including algebra.

North Dakota's Senate voted 40-7 on Wednesday to endorse the measure. It now goes to the state House for additional work.

The measure's critics said they applauded its concept, but some wondered whether it would overlook vocational and technical students and students who preferred the liberal arts.

"Not everybody is a math and science person," said Sen. Carolyn Nelson, D-Fargo, a retired North Dakota State University mathematics instructor.

Sen. Tom Fiebiger, D-Fargo, said the legislation did not include any incentive for students who benefited from the program to stay in North Dakota after they graduated.

Under Grindberg's bill, the tuition grants would not begin until the fall of 2012. They would pay 65 percent of a student's tuition bill to start, with the share gradually climbing to 100 percent.

Grindberg's legislation would set aside $25 million in a special fund for the grants during the 2007-09 budget period, and another $40 million during the subsequent two-year cycle.

The bill is SB2347.

Robinson said he would be pleased to see the grants program funded right away in its first two years, rather than having disbursements stretched out.

"In today's competitive marketplace, even if you're on the right road, someone is going to run right over you," Robinson said. "Are we going to engage, and lead, or are we going to stand back and watch?"