NEW YORK (CNN/Money) - Alcon Inc., the world's largest maker of eye-care products, inched up by 3 percent Thursday in its market debut.

Shares of Alcon (ACL: Research, Estimates) closed at $34, for a $1 gain on the New York Stock Exchange.

Alcon raised $2.3 billion late Wednesday when it sold 69.75 million shares at $33 each, the midpoint of its $31-to-$35 price range, via lead underwriters Credit Suisse First Boston and Merrill Lynch.

Alcon, a unit of Swiss food conglomerate Nestle, makes pharmaceutical, surgical, and contact lens and vision-care products. After the initial public offering, Nestle will own about 75 percent of Alcon common shares if underwriters exercise their over-allotment option to buy 7 million shares.

The Nestle subsidiary has the year's biggest IPO so far, but an even bigger blue-chip deal is waiting to trade. The offering by Travelers Property Casualty Corp. is expected to price its deal later Thursday.

Travelers plans to sell 210 million shares at $16-to-$19 each via Salomon Smith Barney. At $3.7 billion, the Travelers issue is the largest insurance IPO ever and will trade as TAP.A on the NYSE.