SCOTTSDALE, ARIZ. ? With some of its biggest names under suspicion and lawmakers demanding action, major league baseball adopted a tougher steroid-testing program that will suspend first-time offenders for 10 days and randomly test players year-round.

The agreement was hailed by baseball management and its union Thursday as a huge step forward but was criticized by some as not going far enough because the penalties are less harsh than those in Olympic sports and amphetamines were not banned.

“I’ve been saying for some time that my goal for this industry is zero tolerance regarding steroids,” commissioner Bud Selig said.

A first positive test would result in a penalty of 10 days, a second positive test in a 30-day ban, a third positive in a 60-day penalty, and a fourth positive test in a one-year ban — all without pay. A player who tests positive a fifth time would be subject to discipline determined by the commissioner.

“It’s more for our protection than anything else,” Boston pitcher Tim Wakefield said.

Under the previous agreement, a first positive test resulted only in treatment, and a second positive test was subject to a 15-day suspension. Only with a fifth positive test would a player subject to a one-year ban.

No player was suspended for steroid use in 2004, the first season of testing with penalties.

“We’re acting today to help restore the confidence of our fans,” Selig said.

Since the old agreement was reached in 2002, baseball has come under increased scrutiny about steroids.

Barry Bonds, Jason Giambi and Gary Sheffield testified before a federal grand jury investigating the Bay Area Laboratory Co-Operative known as BALCO. President Bush mentioned the steroid problem in last year’s State of the Union address.

“I will be surprised if over time this doesn’t take care of the problem virtually completely,” union head Donald Fehr said, speaking by telephone from Los Angeles.

Said St. Louis Cardinals manager Tony La Russa: “I just hope it’s the Cadillac of all policies because that’s what major league baseball needs. There’s no doubt we have a problem.”

The old deal wasn’t due to expire until December 2006, but the union took the rare step of renegotiating a major section of its labor contract. The new rules run until December 2008.

“It appears to be a significant breakthrough,” Sen. John McCain said in Washington.

McCain, who had threatened baseball with legislation, said that is no longer necessary, though he would have preferred a 10- to 15-game suspension for a first offense and a permanent ban for multiple positive tests.

“I would have liked to see amphetamines added to this list,” McCain said.

Still, it wasn’t good enough for World Anti-Doping Agency chairman Dick Pound, a member of the International Olympic Committee since 1978.

“Basically, instead of having to hold up the liquor store five times before you get a one-year suspension, you only have to hold it up four times,” he said. In addition to one mandatory test each season, players will be randomly selected for additional tests, with no limit on the number, and for the first time will be subject to random tests during the offseason.