The tablet market took a hit in the first quarter after weak demand and a worse-than-expected seasonal decline after the holiday season caused an unexpected decline in shipments, according to a new report from International Data Corporation (IDC).

The research firm reports that global tablet shipments fell 28 percent quarter-over-quarter in the first three months of the year to 7.2 million units.

“We expect the rest of the year to be much stronger, but we believe vendors who continue to focus on the telco channel for distribution will face serious challenges,” said Bob O’Donnell, IDC vice president of clients and displays, in the firm’s report.

Shipments of the iPad were lower than predicted due to supply chain problems with the tablet’s display as well as the advance news of the iPad 2 several weeks ahead of its commercial availability, which prompted some consumers to hold off on buying the tablet until the most recent version was released.

Sales of rival tablets by manufacturers such as Samsung and Motorola were “stymied” by data plan contracts attached to the devices by operators, IDC said. Android-based tablets now comprise 34 percent of the tablet market, an 8 percent increase from the fourth quarter of 2010.

Despite the grim numbers, IDC raised its 2011 shipment forecast for tablets to 53.5 million units from its previous projection of 50.4 million units. The firm expects sales to improve as new tablets come to market in the second half of this year.

The firm also said that Barnes & Noble’s Nook Color took the lead in the eReader market for the first time in the opening quarter of this year as customers turned away from the Kindle’s grayscale-only display.

“Amazon’s Kindle was second, but the lack of a color offering has clearly impacted the company’s previous dominance in the eReader market,” IDC said in its report.

The research firm estimates that 3.3 million eReaders shipped in the first quarter with 105 percent year-over-year growth. IDC expects eReader shipments to rise 24 percent over last year in 2011, to 16.2 million units.