Twitter, the microblogging service that held an initial public offering last year, paid $36 million to acquire 900 patents from IBM according to a filing. The agreement, which was was signed in December and announced in January without financial details, resolved a dispute that prompted IBM to write to Twitter about possible infringement of at least three patents. Twitter now has 956 patents and about 100 filed patent applications in the U.S., it said in the filing yesterday with the U.S. Securities and Exchange Commission. Before its November IPO, Twitter held only nine patents, making it a target for intellectual-property disputes. The deal with IBM was Twitter’s first for patent technology, not counting intellectual property gained by buying other companies. IBM has been granted the most U.S. patents of any company for 21 straight years.