The Chicago Cubs now have two reasons to give thanks to the Montreal Expos.

Last year, the Expos gave up Andre Dawson, who won the National League Most Valuable Player award despite the Cubs' last place finish in the N.L. East.This year, the Cubs have to thank Montreal for giving up on Vance Law, who is now Chicago's starting third baseman.

The Expos chose not to pick up the options Law had in his contract for the 1988 and '89 seasons and allowed him to become a free agent.

The Cubs, who wanted to trade third baseman Keith Moreland to San Diego, signed Law in December and immediately traded Moreland.

"I fully expected to spend the rest of my career there (in Montreal)," Law said.

"I had given them two very good years, but our relationship deteriorated the last month of last season."

Law, 31, was given the starter's job at third base in Chicago and immediately paid dividends by starting the season with a 16-game hitting streak, his career high. His .279 batting average through the first three weeks was also above his career average of .253.

"I played here with the White Sox when Keith was here so I know how popular he was," said Law, a seven-year veteran.

"I didn't want fans on my back, so it was nice to get off to a good start and pulling my weight a little bit."

Law primarily played second base for the Expos last year, although he had 17 games at first and 22 at third. But he found himself being platooned at second base with Casey Candaele, which was the first sign his option might not be picked up.

"They said I didn't have enough range to play second base," said the 6-foot-1 Law without identifying the critics.

"I felt my range was adequate, but being a big guy . . . well, the smaller guys look like they are going quicker than the big guys. I think (Craig) Reynolds (6-1, Houston) has outstanding range, but sometimes people say he doesn't have the kind of range that, say, a Juan Samuel (5-11, Philadelphia) has. I think he has great range, he's just a big guy playing second base."

The deal worked out well for Law because he was put at his favorite position.

"I love playing third," he said. "It's nice to be back in a position where I feel I am best suited. I don't get criticized quite so much.

"I have a chance to use my arm, which I think is one of my best assets. At second base, you make an 80-foot flip and no one knows you can throw. Also, at third, you don't have time to think on most balls. They get there just like that and I prefer that, I prefer trying to make the play at the spur of the moment."

Law has a huge defensive edge at third over Moreland, who was moved to that position from the outfield to make room for Dawson in right field. Through 17 games, Law had two errors for a better rate than Moreland's 28 errors in 148 starts in 1987.

"Being in this division the last three years, the guys on this team knew what kind of player I was," he said.

"I don't think I surprised anybody. You like to come over and get off to a good start, to give them and the fans a good impression."