(1)This section applies if, at a time when the employee has a beneficial interest in them, the shares are converted into shares of a different class in pursuance of an entitlement to convert them which has been conferred on the holder.
(2)The taxable amount determined under section 439 counts as employment income of the employee for the relevant tax year.
(3)The “relevant tax year” is the tax year in which the conversion occurs.
(4)This section is subject to—
section 440 (case outside charge under this section: conversion of entire class), and
section 441 (case outside charge under this section: acquisition of conditional interest).