Cotts, 26, led the White Sox and was tied for eighth in the American League with a career-high 70 relief appearances this past season. The Lebanon, Ill., native had a strong first half, going 1-2 with a 2.95 ERA, but struggled in the second half, finishing with a 5.17 ERA on the season. Cotts posted a 2.77 road ERA and limited first batters faced to a .215 average, while his 14 holds ranked second on the club.
"He gives us another quality arm and a guy we think will only get better," Hendry said. "He's proven he is an effective reliever and one we think will really help us. We're very happy to get him."
Aardsma, 24, posted a 3-0 record with a 4.08 ERA in 45 relief appearances for the Cubs last season. The right-hander also pitched with San Francisco in 2004, and owns a 4-0 career record with a 4.52 ERA (32 ER/63 2/3 IP).
Vasquez, 23, was signed as a non-drafted free agent by the Cubs in 2000. He has spent his entire career within the Cubs organization, most recently going 6-5 with three saves and a 2.75 ERA in 54 relief appearances between Class A Daytona and Double-A West Tenn in 2006.
One of the reasons the White Sox felt they could part with Cotts was the presence of some other young relievers on the 40-man roster.
"We are comfortable with what we have from the left side in [Boone] Logan and [Paulino] Reynosa coming up," Williams said. "So the left side issues aren't as prevalent as having another reliable right-handed guy, a young guy like Aardsma who can come in, you get to our bullpen early and you've got to face him and the other guys coming in behind him."
The trade was a mild surprise in that it was widely expected that the White Sox, if they were going to deal pitching, would move one of their many starters.
"That's what everyone generally wants to talk to us about ... our starting pitching. And quite frankly, unless we're able to improve the '07 club and make us a better in one area or another and additionally get some youth in to protect ourselves in the rotation for the future, we're just not probably going to travel down that road," Williams said. "I've had some feelers out along those lines but obviously not to the point where they've been good enough at this point.
"It wouldn't surprise me when all is said and done to make a deal, but it wouldn't surprise me if we took a step back and we went in with the same five guys we went in last year; wouldn't surprise me at all."
This marks the first trade between the two Chicago franchises since the Cubs acquired pitcher Matt Karchner in exchange for then-Minor League pitcher Jon Garland on July 29, 1998.
The General Managers Meetings ended Thursday, but Williams' search for more bullpen arms isn't over.
"We don't think we're done yet making our bullpen as good as we can make it," he said. "I don't think we're done. We may be done, but the other teams have a lot to say about that."