Skype Inc. was sued by a Luxembourg company for infringing its patents in a federal court in the United States on Thursday. Via Vadis filed similar lawsuits against the internet video phone company in Europe.

Via Vadis alleged in the lawsuit that Skype used two of its patented data access, as well as management technologies to offer peer-to-peer communication systems, services, products and methods.

It appears that the lawsuit was filed in the U.S. District Court in Delaware just a month after the Microsoft Corp. announced its plans to acquire Skype for $8.5 billion. In the lawsuit, the Luxembourg-based company is seeking damages and asks the court to order the company to discontinue infringing its technology.

Via Vadis has already filed a lawsuit against Skype in Germany and Luxembourg. It has decided to bring its case to the United States now that Skype has been acquired by Microsoft Corp. The court in Luxembourg issued a search order to inspect the offices of Skype in Luxembourg and gather evidences. Skype has appealed and declined to present its source code.

Skype said that it cannot comment on the litigation. Skype offers an application that allows Internet users to make online video and voice calls, as well as chats. It is also popular for its other features such as video conferencing and file transfer. As of 2010, it has 663 million registered users.

Skype is a peer-to-peer system instead of client-server system. It uses background processing on computers with Skype software. On May 10, 2011, Microsoft Corp. has agreed to buy Skype Communications.

U.S. stocks ended an unstable session with moderately higher gains on Thursday. Upbeat earnings on technology, as well as consumer discretionary stocks outperformed the data, which showed that economy grew at a sluggish rate and unemployment rate abruptly increased.

The NASDAQ stock market posted the largest gains after NetApp Inc’s strong profits increased the stock 8.6 percent to $56.19. Meanwhile, Microsoft Corp’s shares rose 2.4 percent to $24.77 following a statement from a top investor that its chief executive should step down.

The Dow Jones industrial average rose 0.13 percent or 15.51 points to 12, 410.17. The S&P’s 500 Index climbed 0.31 percent or 4.13 points to 1,324.60. The Nasdaq Composite Index earned 0.70 percent or 19.5 points to 2,780.64.

However, consumer discretionary division performed best, aided by Tiffany & Co, which was up 8.6 percent at $76.03. The luxury seller increased its outlook after releasing its first-quarter earnings.

Coach Inc., the leather goods company famous for its luxury handbags, released 5 percent increase while clothing-line company Guess reported a 15 percent decrease in quarterly profits. But, stocks rose to 11.2 percent as earnings per share came better than estimated. The S&P consumer discretionary sector index climbed 0.8 percent.

The Goldman Sachs reduced its S&P 500 target for the end of the year from 1,500 to 1,450. It is currently the lowest target decided by the banking firm after Citigroup and UBS increased their profit estimates for S&P companies the previous week.

However, unemployment rate reportedly rose last week and remained at high levels. The gross domestic product in the United States climbed at a 1.8 percent yearly rate in the first quarter. It did not change from the last estimate and is still below the expectations of the analysts for stronger growth.

Obama’s administration is investigating methods to improve tax incentives for corporate investments in the United States, Treasury Secretary Timothy Geithner informed on Wednesday before his meeting with chief financial officers from some of the biggest companies in America.

Geithner said in comments after his speech at John Hopkins University’s School of Advanced International Studies that they are examining whether they can get political support for a big tax change. This change is revenue neutral but would improve incentives for investing in the United States.

He is expected to gather with CFOs of major companies in the U.S that includes Microsoft Corp and Cisco Systems on Friday to discuss ideas for simplifying, as well as trimming the corporate tax that is almost the highest tax in the world of industry.

Corporate tax reform, according to administration officials, is the foundation for a discussion about comprehensive tax. But, it would be difficult to pass any meaningful reform for the next two years if the Congress is divided.

Several White House officials have said that they concur with the companies’ main complaint that the federal corporate tax rate at 35 percent is way too high. Both parties have also agreed that the tax code is too heavy and troublesome.

However, administration officials and other people noted that deductions, as well as loopholes make it uncommon for companies to pay the 35 percent rate.

Dorothy Coleman, the vice-president of tax and economic policy at the National Association of Manufacturers, told that cutting the corporate tax rate is a big issue for the group’s members, many of whom will attend the Friday meeting.

Coleman said that they are looking at the issue as a start of a debate and a sign that the administration is serious.

The Microsoft Corporation had just recently completed their Windows 7 Phone software. This new software will be formally launched to the public on October 11. By November, Windows 7 is expected to be installed on several handsets that are believed to compete with Apple and Google Android smartphones.

Samsung and HTC Corp, as well as other groups of smartphones are expected to release Microsoft-based phones this coming holiday season.

The employees of Microsoft Corp gathered around last month at its Redmond, Washington campus. This marked the completion of their software and revealed how they really want to get themselves back in the fiercely competitive phone market.

However, it is still a question whether the Windows 7 is good enough to turn the iPhone obsolete in the market.

According to Bryan Keane, analyst for the Alpine Mutual Funds that holds the shares of Microsoft, the product cannot just outrun everything that is out in the marketplace. However, Windows 7 might just be better than the other Windows platform.

Microsoft just missed a generation with their last phone operating system, Windows Mobile, admitted by Steve Ballmer, the Microsoft Chief Executive. The Windows Mobile struggled its way in the phone market while iPhone and Android reigned well with their touch screens and fresh applications.

Today, Microsoft ranks fourth in the fast-growing operating systems for the smartphone market in the U.S. It is behind Blackberry-maker Research in Motion Ltd, Apple and Google. From comScore research firm, Microsoft has a share of less than 12 percent.