Apple's iPhone 6 Plus has increased its share on the U.S. phablet market in the first three months of 2015, while iPhones as a whole continued to perform well at the major U.S. carriers.

Since its launch, the iPhone 6 Plus has dominated the U.S. phablet market. New data from Kantar Worldpanel, which classifies a phablet as a phone with a screen of 5.5-inches or larger, shows that the 6 Plus' hold has increased to 44% of all phablet sales during Q1 2015. The phablet market itself made up 21% of all U.S. phone sales during the quarter.

Apple also did well overall at the three largest cellular carriers in the U.S., AT&T, Verizon, and Sprint. From Kantar Worldpanel:

Apple's overall sales dominated AT&T, Verizon and Sprint where iPhone represented 59%, 43% and 50% of smartphone sales, while Samsung dominated smartphone sales at T-Mobile with a share of 42%.

People switching from Android made up 11.4% of all new iOS customers in the U.S., down slightly from the 14.6% in the same quarter in 2014.

As noted previously, Apple's latest devices, the iPhone 6 and 6 Plus, already make up 18% of all iPhones in use in the United States. 64% of iPhone owners are also using an iPhone 5 or newer, meaning that they can make use of Apple's latest device, the Apple Watch.

Source: Kantar Worldpanel