HTC has completed the purchase of US graphics chipmaker S3 Graphics, including more than 200 patents which the Taiwanese smartphone maker could potentially use to defend itself against competitors, reports Reuters.

The purchase of S3 Graphics and its 235 patents has been a long time coming after a US$300 million deal was first announced in July 2011. However HTC’s proposed acquisition was brought into question in November 2011 when S3 Graphics lost an ITC complaint alleging that Apple infringed four of its patents. 

In a Reuters interview, HTC CEO Peter Chou said the S3 purchase is “a very good deal” as “HTC as a company needs to invest in patents” – adding that HTC is considering other similar investments.

HTC is involved in a range of patent disputes but Chou said he isn’t concerned about these having a long-term impact on the company. "Patent lawsuits haven't caused any actual damage to HTC. Only the Street is worried for us, we're not worried ourselves. We hope the disputes will get more reasonable in the future," he said.

Legal action from Apple delayed the US launch of one of HTC’s flagship devices and the company was yesterday blocked from using five patents it acquired from Google last year. Apple recently filed a complaint saying that HTC is still infringing patents and demanding that emergency action be taken against 29 of its devices. HTC has also had to modify other devices to comply with an International Trade Commission ruling.

As well as the patent issue, HTC has struggled to compete in the smartphone market over the past year as its devices fail to keep pace with those from Apple and Samsung, both of which have taken market share.

The company warned of lower revenues in the current quarter due to European sales not meeting expectations and US product delays. The company also cut revenue targets on two occasions in the fourth quarter of 2011 while HTC shares recently hit their lowest level in 26 months this week, according to Reuters.

Despite these problems, Chou said HTC it will continue to focus on medium and high-end smartphones. In an interview with The Wall Street Journal this week, the HTC CEO said the company has no plans to enter the low-end smartphone segment, despite wanting to increase its presence in emerging markets.