Japan's Toshiba Corp saw better-than-expected television sales in November and December thanks to a spike in Japanese sales, the head of the company's TV unit told Reuters in an interview on Thursday.

But Masaaki Osumi said sales of 3D models designed for use with special glasses had disappointed, accounting for only about 15-20 percent of large TVs sold, compared with an initial target of 50 percent.

We had wanted 3D sales to make up about half of large-screen TV sales, but it's proving difficult, he said at the Consumer Electronics Show.

The price premium for 3D TVs may still be too high. It's the same in Japan, Europe and America. Sales of 3D TVs with glasses have not lived up to expectations, he said.

Osumi said Toshiba would consider launching passive 3D technology in some regions, which enables viewers to use cheaper, lighter glasses, following LG Electronics' announcement it would push passive 3D.

With 3D technology using glasses, the high price of glasses is a problem, Osumi said.

We want to make the appropriate products for each region. If for example, passive became the main 3D technology in India, or was forecast to become so, we would pursue that aggressively, he said.

Osumi also said Toshiba would meet its 15 million unit TV sales target for the year to March if Japan sales remained flat on the previous year for the next three months.

The world's sixth-largest TV maker by unit sales announced earlier this week it would launch large-screen versions of its ground-breaking glasses-free 3D TV in the United States within the year. Smaller-screen versions went on sale in Japan in December.

Although the need to wear special glasses is seen as a factor behind slow consumer take-up of the technology, rivals like Sony say current glasses-free versions are inferior because they further restrict the angles from which images can be viewed.

Sony put its own glasses-free prototype TVs on show at CES this week.

Toshiba has also hiked its annual TV sales target by a third to 20 million units for the financial year starting in April, despite an expected slump in the Japanese market following the end of a government subsidy program in March and the introduction of digital terrestrial TV in July.

Osumi said he expected the TV unit to stay in profit for the current financial year, but that the following year would be more difficult because of expected weakness in Japan, the company's most profitable market for TVs.

(Editing by Chris Gallagher)