HP is reportedly gearing up to launch five to seven new ultrabooks in the second half of the year.

According to Digitimes, citing Taiwanese suppliers, HP believes it can ship between 3.7 and 5.5 million ultrabooks this year. The first new models could be unveiled by the end of April.

Meanwhile  Acer is also gearing up to launch four new ultrabooks in Q2, basically second-generation S3 and S5 ultrabooks, as well as two cheaper Timeline Ultra 14 and 15 models. Acer hopes to ship 4.5 to 6 million ultrabooks in 2012.

More here.