Shares of Science Applications International Corp. (SAI: chart) rose 21% in their first day of trading Friday after pricing at the high end of an expected range.

In one of the largest IPOs of the current year, the company sold 75 million shares of common stock, which represent about 19% stake in the company. The shares were priced at $15, compared with the expected range of $13 - $15 per share.

SAIC's shares opened up at $17 on the NYSE and closed up at $18.18 a share.

The underwriters have an option to purchase up to 11.25 million additional shares to cover excess demand.

SAIC is a provider of scientific, engineering and technical services to the U.S. military and government agencies.

Morgan Stanley and Bear Stearns were the lead underwriters on the deal.

Also on Friday, the online health insurer eHealth Inc. (EHTH: chart) rose as much as 79% after pricing above a forecast range. The deal was worth $70 million.

The shares opened well above at $25 and ended the first day at $22.90 per share.

The company offered 5 million shares priced at $14, compared with the expected range of $10 - $12 per share.

eHealth follows the succesful first-day performance of recently launched IPOs by tech companies, such as Riverbed Technology (RVBD: chart), CommVault Systems (CVLT: chart) and DivX Inc. (DIVX: chart).

In addition, eHealth has granted the underwriters a 30-day option to buy up to 750,000 additional shares.

Morgan Stanley and Merrill Lynch were the lead underwriters for the offering.

Shipping company Ultrapetrol (Bahamas) Ltd. (ULTR: chart) on Thursday raised $137.5 million, pricing below a forecast range.

The 12.5 million share offering, representing about 44% of the company, sold for $11 per share, compared with a forecast range of $13 - $15 a share.

Underwriters were led by UBS Investment Bank, Bear Stearns and Merrill Lynch. They have an option to purchase up to 1.9 million additonal shares to cover excess demand.

Another company that made good impression on Friday was Acme Packet Inc. (APKT: chart). The computer networking equipment maker on Thursday raised $109 million with an IPO that priced above a forecast range.

The offering of 11.47 million shares, which represents a 20% stake in the company, was priced at $9.50 per share, above the expected range of $8 - $9 per share. The original range of $6.50 - $7.50 a share was lifted earlier on Thursday.

Goldman Sachs, Credit Suisse, J. P. Morgan, and ThinkEquity Partners managed the deal.

In addition, the company has granted the underwriters a 30-day option to buy up to 1.7 million shares to cover over-allotments.

Shares of Acme Packet rose as much as 70%. They opened at $14 and ended the day up to $15.90 a share.