ZURICH (Reuters) - UBS has begun a share buyback program announced earlier this year, and repurchased 44.8 million Swiss francs ($50.21 million) worth of shares last week, the Swiss bank said on Monday.

UBS has said the buyback programme would be worth up to $1 billion this year.

Share buybacks and dividends are seen by analysts as a reason why investors are putting their money into UBS stock since its takeover of longtime rival Credit Suisse last year.

Companies use buybacks to reduce the proportion of stock held by investors, enabling them to return cash to shareholders, and often sending the shares higher.

($1 = 0.8922 Swiss francs)