ALBUQUERQUE, N.M. (AP) _ Former U.S. Secretary of the Interior Manuel Lujan Jr. was in stable condition Saturday following a heart attack he suffered earlier in the week.

The 71-year-old Lujan, a former 10-term New Mexico congressman, had a heart attack Thursday night and underwent surgery at the Heart Hospital of New Mexico.

``It was more serious than a mild heart attack,'' said Vince McVittie, vice president of business development for the hospital.

His wife, Jean Lujan, said doctors plan to release her husband early next week.

Lujan has suffered from cardiac problems for years. He had a heart attack in 1983 and underwent a triple bypass. In 1996, both he and his brother, Edward, spent time in the hospital after suffering mild heart attacks just days apart.

Lujan, a Republican, served 20 years in the U.S. House from the 1st Congressional District. He retired in 1988. President Bush appointed him secretary of the Interior Department in 1989, an office he held for four years.