Apple has pushed past arch-rival Microsoft to become the world's biggest technology company.

Changes in the share price values of the two in Wednesday's choppy trading left the total value of Apple at $222bn (£154bn).

Microsoft is now valued by investors at $219bn.

The worth, known as market capitalisation, is calculated by multiplying the number of shares in a company by the current share price.

Although Apple shares closed down 0.4%, Microsoft fell by 4%.