39. Retained earnings and other reserves
(a) Retained earnings
Retained earnings comprise net profits retained in the Group after the payment of equity dividends. There are no significant statutory, contractual or exchange control restrictions on distributions by Group undertakings.
(b) Other reserves
(i) Movements in reserves
| Merger reserve US$m | Hedging reserve US$m | Translation reserve US$m | Own shares reserve US$m | Total other reserves US$m | |
| At 1 April 2021 | (15,682) | 13 | (1,303) | (1,006) | (17,978) |
| Purchase of shares by employee trusts | — | — | — | (61) | (61) |
| Purchase of shares held as treasury shares | — | — | — | (111) | (111) |
| Other vesting of awards and exercises of share options | — | — | — | 49 | 49 |
| Change in the fair value of hedging instruments recognised in OCI | — | (24) | — | — | (24) |
| Amounts reclassified from OCI to the Group income statement | — | 26 | — | — | 26 |
| Currency translation gains | — | — | 35 | — | 35 |
| At 31 March 2022 | (15,682) | 15 | (1,268) | (1,129) | (18,064) |
| Merger reserve US$m | Hedging reserve US$m | Translation reserve US$m | Own shares reserve US$m | Total other reserves US$m | |
| At 1 April 2020 | (15,682) | 11 | (1,367) | (1,183) | (18,221) |
| Shares delivered as consideration for acquisition | — | — | — | 90 | 90 |
| Other vesting of awards and exercises of share options | — | — | — | 87 | 87 |
| Change in the fair value of hedging instruments recognised in OCI | — | 35 | — | — | 35 |
| Amounts reclassified from OCI to the Group income statement | — | (33) | — | — | (33) |
| Currency translation gains | — | — | 64 | — | 64 |
| At 31 March 2021 | (15,682) | 13 | (1,303) | (1,006) | (17,978) |
(ii) Nature of reserves
The merger reserve arose on the demerger from GUS plc in 2006 and is the difference between the share capital and share premium of GUS plc and the nominal value of the share capital of the Company before a share offer at that date.
Movements on the hedging reserve and the position at the balance sheet date reflect hedging transactions, originating from the management of foreign exchange risk, which are not charged or credited to the Group income statement, net of related tax.
Movements on the translation reserve and the position at the balance sheet date reflect foreign currency translations since 1 April 2004 which are not charged or credited to the Group income statement, net of related tax. The movement in the year ended 31 March 2022 comprises currency translation gains of US$35m (2021:US$64m) recognised directly in Other comprehensive income.
The balance on the own shares reserve is the cost of ordinary shares in the Company and further details are given in note 39(b)(iii). The difference between the amounts shown in the Group and Company financial statements in respect of this reserve arose due to translation of pound sterling amounts into US dollars at different exchange rates on different translation dates.
(iii) Movements in own shares held and own shares reserve
| Number of own shares held | Cost of own shares held | ||||||
| Treasury million | Trusts million | Total million | Treasury US$m | Trusts US$m | Total US$m | ||
| At 1 April 2021 | 52 | 4 | 56 | 871 | 135 | 1,006 | |
| Purchase of shares by employee trusts | — | 2 | 2 | — | 61 | 61 | |
| Purchase of shares held as treasury shares | 3 | — | 3 | 111 | — | 111 | |
| Transfers | (6) | 6 | — | (87) | 87 | — | |
| Other vesting of awards and exercises of share options | — | (4) | (4) | (8) | (41) | (49) | |
| At 31 March 2022 | 49 | 8 | 57 | 887 | 242 | 1,129 | |
| Number of own shares held | Cost of own shares held | ||||||
| Treasury million | Trusts million | Total million | Treasury US$m | Trusts US$m | Total US$m | ||
| At 1 April 2020 | 60 | 8 | 68 | 973 | 210 | 1,183 | |
| Shares delivered as consideration for acquisition | (7) | — | (7) | (90) | — | (90) | |
| Other vesting of awards and exercises of share options | (1) | (4) | (5) | (12) | (75) | (87) | |
| At 31 March 2021 | 52 | 4 | 56 | 871 | 135 | 1,006 | |