It didn't take Manager Joe Altobelli long to figure out why his Baltimore Orioles lost, 10-8, to the Milwaukee Brewers tonight.

Cecil Cooper already had summarized the dismal night for Orioles pitchers. He'd doubled to left field off reliever Sammy Stewart to score Robin Yount from first base with two out in the ninth inning. Ben Oglivie just made things worse when he singled to score Cooper.

"We had two outs and let them score two runs in the eighth and ninth innings," Altobelli said. "That's not very smart pitching."

Besides that, he cited the nine walks his pitchers gave up and the Orioles' failure to score in the seventh when they had the bases loaded and nobody out.

The one bright spot came in that seventh inning when Eddie Murray singled to center to extend his hitting streak to 19 games. He is three games shy of the club record set by Doug DeCinces in 1978-79.

At the time of Murray's single, it appeared the Orioles would add to their 13 victories in their last 18 games. They had chased three Brewers pitchers and led, 8-6. But when Jim Sundberg's two-run homer just cleared the glove of left-fielder Al Bumbry, the Brewers tied the game for the third time.

"I couldn't tell whether he got a glove on it or not," Altobelli said. "He went back to the fence and jumped. He just couldn't get it."

Stewart gave up the home run to Sundberg as well as Cooper's RBI double in the ninth. When Tippy Martinez relieved Stewart in the ninth, he became the Orioles' fifth pitcher. Tom Tellman (6-3), the Brewers' fourth, won in relief of Mike Caldwell. Ray Searage pitched a hitless ninth to earn his first save.

"Things kind of run in patterns," Tellman said. "There's a couple of guys who, no matter what, when I follow them I don't do well. But I always seem to do well for Caldwell."

Tellman and Searage were the only pitchers who could claim credit for anything tonight. The tone was set in the second inning when the Brewers tagged starter Dennis Martinez for four runs and the Orioles followed with four in the bottom of the second.

Ken Singleton drove in two of his three runs in the second and Rick Dempsey hit his ninth home run of the year, to left, with one on, to tie the score, 4-4.

From that point, the Orioles never trailed until the ninth inning. They took a 6-4 lead in the fourth on John Shelby's two-run, two-out single over the outstretched glove of second baseman Jim Gantner. And after Milwaukee tied the score, 6-6, on Gantner's two-run homer in the fifth, the Orioles drew ahead once again in the bottom of the inning on a double by Gary Roenicke and RBI singles by Singleton and third baseman Ron Jackson.

But after loading the bases with nobody out in the seventh, the Orioles lost control. Nine walks, no runs in the seventh and four Milwaukee runs after two were out. A hard one to lose, but simple to explain. At least for Altobelli.

Left-hander Scott McGregor, who suffered a broken ring finger on his pitching hand Aug. 28, will undergo minor surgery Saturday. A spokesman for the Orioles said a pin will be inserted into the finger to stabilize the bone chips.

McGregor had a 15-12 record and 3.94 ERA. He was injured when a ground ball, hit by California's Brian Downing, took a bad hop and struck his bare hand.