SAN FRANCISCO, Oct 21 (Reuters) - California posted $563.07 million in retail orders on Monday for the $2.2 billion of general obligation bonds it is selling through Tuesday, a spokesman for State Treasurer Bill Lockyer's office said.

Retail investors ordered about 44 percent of the $1.28 billion of the tax-exempt bonds offered to them, the spokesman said, noting the sale includes about $2.06 billion of tax-exempt bonds and about $186.5 million of taxable bonds.

Preliminary yields for the tax-exempt bonds offered Monday included 1.48 percent for a five-year maturity, 3.15 percent for a 10-year maturity and 4.92 percent for a 30-year maturity.

The sale opens to institutional investors on Tuesday.

California's deal this week is the state's biggest general obligation bond offer since April, when it sold $2.72 billion of the debt.