Broadcom and a group led by KKR are emerging as the two leading bidders for Toshiba's semiconductor unit as of Friday's deadline for second-round offers, according to people familiar with the matter.

Broadcom, based in San Jose, California, is offering about ¥2.2 trillion ($20 billion) and would face simpler regulatory reviews than some rivals, said one of the people, asking not to be identified because the matter is private. The competing group, which includes state-backed Innovation Network of Japan and Development Bank of Japan, plans to offer about ¥1.8 trillion and would benefit from support from the country's government, the people said.

Western Digital has been in talks to join the Japan group, but the parties haven't been able to agree on how to divvy up ownership. The company has been offered a stake of less than 20 percent, but it wants a controlling share, they said. Apple, which uses Toshiba memory chips in its products, is still considering whether to contribute capital to one or more bidders, they said.