Updated from 5:43 p.m. EST

Yahoo!

(YHOO)

offered to acquire career-hunting Web site

HotJobs.com

(HOTJ)

in a deal that would be valued at about $436 million in cash and stock.

HotJobs agreed in June to be acquired by

TMP Worldwide

(TMPW)

, the owner of rival online job-hunting outfit Monster.com.

The proposed deal, which Yahoo! said should be treated as a tax-free reorganization for HotJobs shareholders "in most circumstances," marks the first time in recent memory that an Internet company has been the object of a bidding war.

The unsolicited bid also represents the first major acquisition attempt by Yahoo! since the company, led by new Chairman and CEO Terry Semel,

detailed its strategy last month for diversifying its advertising-dominated revenues.

In a press release after the close of regular trading, Yahoo! said it would pay $10.50 a share for HotJobs, which ended the day at $6.47. The 52-week high is $14.38. Yahoo! finished Wednesday at $19.14.

At TMP Worldwide's Wednesday close of $45.05, down 13 cents, that company's all-stock bid for HotJobs amounts to $9.89 a share. HotJobs has said that it expects the TMP Worldwide deal to close in the first quarter of 2002 at the latest.

HotJobs and TMP Worldwide didn't respond immediately to requests for comment.

Yahoo! has contacted Dimitri Boylan, the CEO of HotJobs, with the offer, which was unanimously approved by Yahoo!'s board. Yahoo! said it hopes to begin merger discussions as soon as possible and contended that "our offer provides HotJobs shareholders with superior value, less regulatory risk, and faster execution than HotJobs's pending merger with TMP Worldwide."

Yahoo! said it would use its existing cash balances to finance the cash portion of the consideration.