Janus Capital Corp. fund managers plowed several billion dollars into Internet stocks during the first half of this year, dramatically boosting their bets on volatile and often-risky Web companies.

The recent Web investments, including stakes in eBay Inc. and Amazon.com Inc., mark a shift at Denver-based Janus, the seventh-biggest U.S. mutual fund manager. Until late last year, Janus had only one major direct Internet stake--America Online Inc.--along with several indirect bets on companies contributing to the growth of the World Wide Web.

Shareholder reports disclose that Janus funds made more pure Internet plays in late 1998 and picked up their purchases earlier this year. During the six months ended April 30, Internet stocks rose to 24 percent of assets from 0.8 percent at the Janus Venture Fund, for example, and to 20.4 percent from 5.3 percent at the Janus Mercury Fund.

"That's very bold by any standard," said Russ Kinnel, a mutual fund editor at Morningstar Inc., a Chicago-based company that provides information on mutual funds and stocks. "They are not just new to the Internet, but clearly they have ramped up their investments there."

The Janus funds bought Internet stocks worth about $3.2 billion, at current prices, during the first seven months of this year, according to regulatory filings. The actual amount spent by the funds may be different because many Internet stocks surged during the early months of 1999 before falling during more recent months.

Janus, a unit of Kansas City Southern Industries Inc., began moving into Web stocks before a recent drop in Internet shares. Its funds, though, didn't suffer the big declines seen in many Web companies in July, when the Interactive Week Internet index fell 11 percent. The Janus Twenty and Janus Mercury funds, for example, each fell about 4 percent during the month, and the Janus Olympus fund fell 2.2 percent. The Standard & Poor's 500 fell 3.2 percent in July.

Janus's Internet shopping spree included the purchase of 12.6 million shares this year in Amazon.com, the Internet retailer. Janus Capital, which reports the combined holdings of the mutual fund group under its own name, now ranks as the largest institutional shareholder at Amazon.com, according to data collected by Technimetrics Inc.

Other acquisitions during the first half of the year, according to filings with the Securities and Exchange Commission, included 5.93 million eBay shares; 2.6 million shares of Yahoo Inc.; and 6.9 million shares of Excite Inc., the Internet search service purchased by At Home Corp. in June. By July 30, the Janus funds had acquired about 7 million shares in PSINet Inc., a provider of Internet access services.

Janus portfolio managers didn't organize a concerted effort to invest in the Internet, said a spokeswoman for the fund group. Their tilt toward Internet stocks, though, was apparent through semiannual reports sent to mutual fund shareholders for the six months ended April 30.

"We believe the Internet has the potential to transform not only our economy but also our everyday lives," said James Goff, portfolio manager for the Janus Enterprise Fund. EBay and Amazon.com "are maniacally focused on providing the finest customer experience by continually reengineering their Web sites," said Claire Young, manager of the Janus Olympus Fund.

The online investments were made as investors flocked to the Janus fund group, enticed by high returns. Janus had a net inflow of $18.3 billion from investors during the first half of this year, second only to Vanguard Group, according to Boston-based Financial Research Corp.

Janus has attracted customers by producing stellar results at funds such as the Janus Twenty, which jumped 72 percent last year. Another factor is that Janus funds specialize in large-cap growth stocks, a sector that has been popular.

"The style of management Janus has is predominantly a growth manager," said Dave Haywood, an analyst for Financial Research Corp. "That is an investment style that has been in favor, and Janus does it as well as anybody."

Janus funds also can entail more risk than most of their peers that invest in large-cap growth stocks. According to Morningstar, Janus Twenty's stock portfolio as of March 31 had the sixth-highest price-to-earnings ratio among 258 large-cap growth funds. Four other Janus funds ranked in the top 40.

Linking current performance of Janus funds to Internet stocks is difficult because the funds don't disclose up-to-the-minute information on their holdings. What regulatory filings do show is that at least eight Janus funds had more of their assets in Internet stocks on April 30 than they did on Oct. 31, 1998.

The Janus Enterprise Fund, for example, raised its Internet stake to 17.7 percent of assets on April 30 from 3.7 percent at Oct. 31. Janus Olympus went to 14.9 percent from 4.4 percent. These percentages reflect both the purchase of shares and capital appreciation.

The figures, though, exclude holdings in indirect Web investments by Janus, such as the group's large stakes in Charles Schwab Corp., a leading online broker, and Cisco Systems Inc., which provides Internet "plumbing" such as routers and switches.

When these companies are counted with pure Internet investments, the percentage of assets devoted to online companies increases.