Baseball's winter meetings erupted in a gusher of last-day activity as teams from Baltimore to Atlanta to Detroit to Chicago to New York shouted that they had struck paydirt.

In the day's major news:

* The Orioles signed outfielder Lee Lacy, who had the second-highest batting average in the National League last season (.321) to a four-year guaranteed contract for more than $2 million.

Signing the 35-year-old ex-Pittsburgh Pirate went a long way toward easing the Orioles' offseason chagrin at failing to sign free agent Andre Thornton or complete any of a half-dozen potential trades here.

"We're very happy," said Baltimore General Manager Hank Peters. "We expect Lacy to be one of our regulars in the outfield, in either left or right, but he could be a DH if we acquire another outfielder. He'll bat at the top of the lineup, where we've really needed somebody who can get on base a lot."

According to sources, the Orioles also will go down to the wire next week with the San Diego Padres in the battle to sign free-agent outfielder Fred Lynn, late of the California Angels, for more than a million dollars a year.

* Free-agent relief pitcher Bruce Sutter reached agreement with the Atlanta Braves on a six-year contract. St. Louis Cardinals officials publicly admitted giving up hope of re-signing the 45-save superstar.

Atlanta's contract bid to Sutter is not as outlandish as it might seem at first look. Sources said the Braves offered Sutter an $800,000-a-year salary for six seasons (i.e., $4.8 million), plus a $4.8 million annuity at 13 percent interest, which in 1990 would begin paying Sutter $1.327 million a year for 30 years.

You can call that a $44 million contract. You could also call it less than $10 million for six years.

Sutter, 31, a right-hander, said of the club he is forsaking, the Cardinals "are very dear to me."

He told a news conference his choice between St. Louis and Atlanta might have been different if the Cardinals had used Manager Whitey Herzog to negotiate with him instead of other executives.

He said he had talked with Cardinals management this morning and "they just said, 'Good luck.' " The Detroit Tigers strengthened their chances of repeating as world champions by acquiring sturdy New York Mets right-handed starter Walt Terrell, who was 11-12 in 215 innings last season with a 3.52 ERA. The Tigers gave up third baseman Howard Johnson, a poor fielder with good power and promise, who had 12 homers and 50 RBI in 355 at bats this year.

"I'm as pleased with this as I was the day we got the left-hander this spring (reliever Willie Hernandez, who became American League most valuable player)," said Detroit Manager Sparky Anderson. "Both times, I was shaking all morning hoping nothing would blow it at the last minute. (Seventeen-game winner) Milt Wilcox just had shoulder surgery last week. How do I know how well he'll come back? I know this, we had to have another starter.

"Terrell is a bulldog and he's the sort of sinker-slider pitcher who does well in our park."

* The National League East champion Chicago Cubs sighed in relief as they outbid 17 teams for left-hander Steve Trout, who was drafted by more clubs than any other free agent. The Cubs re-signed the 13-7 pitcher for five seasons at $900,000 a year.

"We made a commitment to baseball, to Chicago and to our players that we would try to keep our team intact," said Cubs General Manager Dallas Green, whose key task is to try to re-sign NL Cy Young award winner Rick Sutcliffe.

"I certainly am going to go after Rick now," Green said, "as far as I can pursue." The New York Yankees went past the deadline twice in their attempts to sign Rickey Henderson of the Oakland A's. The Yankees had a four-for-two trade (in which they would give up pitchers Jay Howell and Jose Rijo and two top minor leaguers) pending with the A's subject to their signing Henderson.

When the Yankees promised that they and Henderson "were close" to a five-year agreement, the A's gave them the full 72 hours provided by baseball rules to complete the deal, rather than the 48 hours they had set Wednesday. Later today, the Yankees said they would need only until midnight tonight, but when that passed, they extended the deadline again, this time until noon Saturday.

There seemed little doubt, however, that Henderson would soon be a Yankee. "This would make my dream come true, to play center field for the Yankees," said Henderson, who flew here for talks. "Just knowing that I'm a Yankee is all I want right now. Helping a team to a World Series is my goal in baseball and getting there with the Yankees would be the best."

* The Milwaukee Brewers traded 280-game winner Don Sutton, who was excellent but snakebitten in a 14-win 1984 season, to the Oakland A's for 13-game winner Ray Burris. Sutton threatened to retire if he wasn't traded closer to his West Coast home, where he has teen-age children, and Burris had formally demanded a trade.

"Both teams and both players were accommodated," said Brewers General Manager Harry Dalton. "We couldn't get Don to the golden triangle (Dodgers-Angels-Padres), but at least we got him in the state (of California)."

That wasn't good enough, Sutton said when told of the trade. "I'm not pleased. I'm not happy," he said. Saying Oakland was not close enough and the fact it is a 50-minute flight from his home "no consolation," Sutton indicated he may decide to retire if he can't "move out of this emotional, angry mood." The trade will stand in any event. The Chicago White Sox made two trades with Montreal within hours. The first sent third baseman Vance Law (17 home runs, 59 RBI) to the Expos for hard-throwing reliever Bob James, who had a 3.66 ERA and 91 strikeouts in 96 innings this year. The White Sox also got infielder Bryan Little for pitcher Bert Roberge.

This day's two happiest teams could well be the Orioles and the Tigers. Baltimore got something of real value for nothing (except money) and the Tigers made what looks like a dream trade.

"We can cover up third base with Tom Brookens and Marty Castillo. They can catch everything, even if we give up some hitting," said Anderson. "But you can't cover up pitching."

The Mets, weak at third base, are gambling that Johnson will blossom into a real power hitter -- something the Tigers have been expecting for years. "Johnson was our top prospect," admitted Tigers General Manager Bill Lajoie.

"It's a very important acquisition when you get the second-leading hitter in the National League," Baltimore's Peters said of Lacy. "His defense and arm are acceptable and he has some speed (20 steals). He and Mike Easler have had similar careers. They were platooned with each other for years, then, last year, Easler was traded (to Boston) and they both got to play regularly for the first time. They both had the best seasons of their careers. That impressed us.

"You can only put nine on the field at once and when you add a player who's going to be one of those nine every day, you feel you've really improved your club."

Lacy will be 36 the first week of 1985 season, but has hit .300 for three straight years and, last season, was third in baseball in outfield assists (15).

"There were a half-dozen trades we could have made here," Peters said, "but it's not life and death that we make a deal . . . Don't confuse change with progress . . . All those deals would have involved breaking up our pitching staff and we don't want to do that."

For once, in the case of Lynn, Baltimore will be involved in a free-agent struggle with a city and team of comparable size and financial resources. The Padres shouldn't be able to outbid the Orioles by a lot.

Lynn made $1.4 million with the Angels last season. The Orioles declined to offer Thornton $4.4 million over four years, before he re-signed with Cleveland.

"I hope to hear on Lynn by next week," Peters said. "I still feel like we have a chance."