Barnes & Noble received a boost in its patent infringement case against Microsoft after staff attorneys at the US International Trade Commission recommended that ITC Judge Theodore Essex find that the book company had not infringed on three Microsoft patents, reports Bloomberg.

Microsoft brought the case against Barnes & Noble in March of last year, claiming that the NOOK and NOOK Color tablets infringed on five patents. In the run up to the eventual hearings, Redmond dropped two of the patents from the case, with three remaining.

Essex discarded Barnes & Noble's affirmative defense in which the company alleged that Microsoft's attempt to assert patents against Android was a breach of antitrust law, leaving subsequent discussion to revolve around the validity and applicability of Microsoft's patents. The ITC lawyers, acting as an independent third party and giving their own assessment of the evidence presented, argue that there is no infringement case to answer.

After Essex has reviewed the relevant evidence presented by Microsoft, Barnes & Noble, and the ITC's own lawyers, he is expected to release his findings on April 27th. This initial determination will then be reviewed by an ITC panel, which will make the final decision on the case's outcome.

The software giant is downplaying the significance of the ITC lawyers' position. In a statement, a company representative said, "This was a preliminary argument by the Office of Unfair Import Investigations ('OUII') staff attorney, which was filed before the presentation of the evidence at the hearing has occurred. The OUII staff may change its position after the hearing. Additionally, the administrative law judge will hear the evidence and arguments at the hearing and will come to his own conclusion."